TRANSDERMAL DELIVERY SYSTEMS FOR ACTIVE AGENTS
A delivery vehicle for topical pharmaceutical formulations that include a C2 to C4 alkanol, a polyalcohol, and a monoalkyl ether of diethylene glycol present in relative amounts sufficient to provide permeation enhancement of an active agent through mammalian dermal or mucosal surfaces. Preferably, the delivery vehicle as well as the formulations that contain it are substantially free of long-chain fatty alcohols, long-chain fatty acids and long-chain fatty esters in order to avoid potential undesirable odor and irritation effects caused by such compounds during use of the formulation. Without these additives, use of the formulations is facilitated and patient compliance is greater
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This application is a continuation of application Ser. No. 12/614,216 filed Nov. 6, 2009, which is a continuation-in-part of application Ser. No. 10/798,111 filed Mar. 10, 2004, which claims the benefit of each of application Nos. 60/453,604 filed Mar. 11, 2003 and 60/510,613 filed Oct. 10, 2003. Application Ser. No. 12/614,216 is also a continuation-in-part of application Ser. No. 11/755,923 filed May 31, 2007, which is a continuation-in-part of U.S. patent application Ser. No. 11/371,042 filed Mar. 7, 2006, now U.S. Pat. No. 7,335,379, which is a continuation of International application no. PCT/EP2004/011175 filed Oct. 6, 2004, which claims the benefit of U.S. provisional patent application No. 60/510,613, filed Oct. 10, 2003. Application Ser. No. 11/755,923 is also a continuation-in-part of U.S. patent application Ser. No. 11/634,005 filed Dec. 4, 2006, now U.S. Pat. No. 7,404,965, which is a continuation of application Ser. No. 10/343,570 filed May 19, 2003, now U.S. Pat. No. 7,214,381, which is the U.S. national stage of International application no. PCT/EP01/09007 filed Aug. 3, 2001 which claims priority to International application no. PCT/EP00/07533 filed Aug. 3, 2000. Each prior application is expressly incorporated herein in its entirety by reference thereto.
TECHNICAL FIELDThe present invention relates to a novel transdermal or transmucosal pharmaceutical formulation comprising at least one active ingredient and a solvent system. The invention reveals a pharmaceutical formulation that administers the active drug(s) at a permeation rate that would ensure therapeutically effective systemic concentration. The formulations of the present invention contain defined amounts of chemicals that minimize the barrier characteristics of the most uppermost layer of the epidermis and provide sustained permeation rate. This invention relates generally to a novel delivery vehicle and preferably one that is substantially free of long chain fatty alcohols, long chain fatty acids, and long-chain fatty esters.
BACKGROUNDThe present invention relates to formulations and methods of treatment using a wide variety of active agents. Of course, many existing agents and treatments are currently known.
In the area of hormones, for example, reduced levels of endogenous steroid hormones in humans often leads to a variety of undesirable clinical symptoms. For example, men with low testosterone levels (hypogonadism) may result in clinical symptoms including impotence, lack of sex drive, muscle weakness, and osteoporosis. Similarly, in women, reduced levels of testosterone and/or estrogen may result in female sexual disorder, which include clinical symptoms such as lack of sex drive, lack of arousal or pleasure, low energy, reduced sense of well-being, and osteoporosis. Moreover, reduced levels of estrogen and/or progesterone in women, such as that due to menopause, often result in clinical symptoms including hot flashes, night sweats, vaginal atrophy, decreased libido, and osteoporosis.
In addition to reduced levels of endogenous steroid hormones such as those described above, adrenal insufficiency leads to reduced levels of dehydroepiandrosterone (DHEA) in men and women. The adrenal glands are also involved in the production of many hormones in the body, including DHEA and sex hormones such as estrogen and testosterone. Consequently, adrenal insufficiency can lead to reduced levels of DHEA and sex hormones which can lead to the clinical symptoms described above.
Although steroid hormone concentrations may be restored to normal or near-normal levels by hormone replacement therapy, the current forms of treatment (i.e., oral, intramuscular, subcutaneous, transdermal patches and topical formulations) have several disadvantages. For example, orally administered testosterone is largely degraded in the liver, and is therefore not a viable option for hormone replacement since it does not allow testosterone to reach systemic circulation. Further, analogues of testosterone modified to reduce degradation (e.g., methyltestosterone and methandrostenolone) have been associated with abnormalities to liver function, such as elevation of liver enzymes and conjugated bilirubin. Injected testosterone produces wide peak-to-trough variations in testosterone concentrations that do not mimic the normal fluctuations of testosterone making maintenance of physiological levels in the plasma difficult. Testosterone injections are also associated with mood swings and increased serum lipid levels. Injections require large needles for intramuscular delivery, which leads to diminished patient compliance due to discomfort. Commonly, estrogen is often administered orally. This route of administration has been also associated with complications related to hormone metabolism, resulting in inadequate levels of circulating hormone. Further, side-effects seen with the use of oral estrogen include gallstones and blood clots. To overcome these problems, transdermal delivery approaches have been developed to achieve therapeutic effects in a more patient friendly manner.
The art recognizes that the transdermal and/or transmucosal delivery of active agents provide a convenient, pain-free, and non-invasive method of administering active agents to a subject. Topical or transdermal delivery systems for the administration of drugs are known to offer several advantages over oral delivery of the same drugs. For example, the administration of active agents through the skin or mucosal surface avoids the well-documented problems associated with the “first pass effect” encountered by oral administration of active agents.
Generally, the advantages of topical or transdermal delivery of drugs relate to pharmacokinetics. More specifically, one common problem associated with the oral delivery of drugs is the occurrence of peaks in serum levels of the drug, which is followed by a drop in serum levels of the drug due to its elimination and possible metabolism. Thus, the serum level concentrations of orally administered drugs have peaks and valleys after ingestion. These highs and lows in serum level concentrations of drug often lead to undesirable side effects.
In contrast, topical and transdermal delivery of drugs provides a relatively slow and steady delivery of the drug. Accordingly, unlike orally administered drugs, the serum concentrations of topically or transdermally delivered drugs are substantially sustained and do not have the peaks associated with oral delivery.
Although the transdermal and/or transmucosal delivery of active agents overcome some of the problems associated with oral administration of the same agents, this route of administration is not free of its own drawbacks. Transdermal patches very often cause allergic reactions and skin irritations due to their occlusive nature, or due to their composition (incompatibility reactions with the polymers or adhesives that are used).
In addition to skin irritation and tolerance considerations, another issue of transdermal drug delivery systems is that these systems are typically restricted to low-molecular weight drugs and those with structures having the proper lipophilic/hydrophilic balance. High molecular weight drugs, or drugs with too high or too low hydrophilic balance, often cannot be incorporated into current transdermal systems in concentrations high enough to overcome their impermeability through the stratum corneum. Efforts have been made in the art to chemically modify the barrier properties of skin to permit the penetration of certain agents (since diffusion is primarily controlled through the stratum corneum), enhance the effectiveness of the agent being delivered, enhance delivery times, reduce the dosages delivered, reduce the side effects from various delivery methods, reduce patient reactions, and so forth. In this regard, penetration enhancers have been used to increase the permeability of the dermal surface to drugs.
Efforts have been made in the art to chemically modify the barrier properties of skin to permit the penetration of certain agents (since diffusion is primarily controlled through the stratum corneum), enhance the effectiveness of the agent being delivered, enhance delivery times, reduce the dosages delivered, reduce the side effects from various delivery methods, reduce patient reactions, and so forth.
The most common penetration enhancers, however, are toxic, irritating, oily, odiferous, or allergenic. Specifically, the penetration enhancers used and thought to be necessary to transdermally deliver hormones or other active agents such as oxybutynin, namely, long-chain acids such as oleic acid or lauric acid, long-chain alcohols such as lauryl or myristyl alcohol, and long-chain esters such as triacetin (the glycerol trimester of acetic acid), glycerol monolaurate or glycerol monooleate, tend to include aliphatic groups that make the formulations oily and malodorous.
For example, U.S. Pat. No. 5,891,462 teaches the use of lauryl alcohol as a permeation enhancer for estradiol and norethindrone acetate. Such formulations are not appealing to the user nor to anyone else in close proximity to the user. Although this particular patent discloses three examples of estradiol or norethindrone acetate formulations having no lauryl alcohol component, such formulations are comparative examples that are intended to illustrate the long held position that long chain fatty alcohols such as lauryl alcohol are necessary to transdermally deliver norethindrone acetate in combination with estradiol to a subject.
Additionally, for example, the known testosterone gel formulations FORTIGEL® and TOSTRELLE® (Cellegy Pharma, South San Francisco, Calif.), both include ethanol, propanol, propylene glycol, carbomer, triethanolamine, purified water, and oleic acid as a permeation enhancer, the latter being responsible for the irritating and malodorous characteristics of these formulations. Also, TESTIM® (Auxilium Pharmaceuticals, Norristown, Pa.) is a 1% testosterone gel and includes pentadecalactone, acrylates, glycerin, polyethylene glycol (PEG), and pentadecalactone as a permeation enhancer. It is a very odoriferous compound. Also, TESTIM® is not desirable because it contains undesirable amounts of glycerin which are not well tolerated by the skin.
For these reasons, other penetration enhancers have been used to increase the permeability of the dermal surface to drugs. Many of these are proton accepting solvents such as dimethyl sulfoxide (DMSO) and dimethylacetamide. Other penetration enhancers that have been studied and reported as effective include 2-pyrrolidine, N,N-diethyl-m-toluamide (Deet), 1-dodecal-azacycloheptane-2-one N,N-dimethylformamide, N-methyl-2-pyrrolidine, calcium thioglycolate, hexanol, fatty acids and esters, pyrrolidone derivatives, derivatives of 1,3-dioxanes and 1,3-dioxolanes, 1-N-dodecyl-2-pyrrolidone-5-carboxylic acid, 2-pentyl-2-oxo-pyrrolidineacetic acid, 2-dodecyl-2-oxo-1-pyrrolidineacetic acid, 1-azacycloheptan-2-one-2-dodecylacetic acid, and aminoalcohol derivatives, including derivatives of 1,3-dioxanes, among others. Some of these permeation enhancers also present odor or even taste disadvantages.
In addition, transdermal drug delivery systems are typically restricted to low-molecular weight drugs and those with structures having the proper lipophilic/hydrophilic balance. High molecular weight drugs, or drugs with too high or low hydrophilic balance, often cannot be incorporated into current transdermal systems in concentrations high enough to overcome their impermeability through the stratum corneum. Specifically, polar drugs tend to penetrate the skin too slowly, and since most drugs are of a polar nature, this limitation is significant.
Further, transdermal delivery from semi-solid formulations faces antinomic requirements. The drug delivery system should enable absorption of an extensive amount of active drug through the skin within the shortest period of time in order to prevent contamination of individuals, transfer to clothing or accidental removing. The drug delivery system should also provide sustained release of the active drug over 24 hours ideally, so that only once-daily application is required. This drug delivery system should also prevent drug crystallization at the application surface area.
Drug delivery systems having such properties may be achieved by combining various solvents. A volatile solvent may be defined as a solvent that changes readily from solid or liquid to a vapor, that evaporates readily at normal temperatures and pressures. Here below is presented data for some usual solvents, where volatility is reflected by the molar enthalpy of vaporization ΔvapH, defined as the enthalpy change in the conversion of one mole of liquid to gas at constant temperature. Values are given, when available, both at the normal boiling point tb, referred to a pressure of 101.325 kPa (760 mmHg), and at 25° C. (From “Handbook of Chemistry and Physics, David R. Lide, 79th edition (1998-1999)—Enthalpy of vaporization (6-100 to 6-115). Stanislaus et al. (U.S. Pat. No. 4,704,406 on Oct. 9, 2001) defined as volatile solvent a solvent whose vapor pressure is above 35 mm Mg when the skin temperature is 32° C., and as non-volatile solvent a solvent whose vapor pressure is below 10 mm Mg at 32° C. skin temperature. Examples of non-volatile solvents include, but are not limited to, propylene glycol, glycerin, liquid polyethylene glycols, or polyoxyalkylene glycols. Examples of volatile solvents include, but are not limited to, ethanol, propanol, or isopropanol.
Numerous authors have investigated evaporation and transdermal penetration from solvent systems. For Example, Spencer et al. (Thomas S. Spencer, “Effect of volatile penetrants on in vitro skin permeability”, AAPS workshop held in Washington D.C. on Oct. 31-Nov. 1, 1986) established that the relationship between volatility and penetration is not absolute and depends on many parameters such as for instance hydration of the tissue or the solubility of the penetrant in the tissue. Stinchcomb et al. reported that the initial uptake of a chemical (hydrocortisone, flurbiprofen) from a volatile solvent system (acetone) is more rapid than that from a non-volatile solvent system (aqueous solution). With an aqueous solution, close to the saturation solubility of the chemical, the driving force for uptake remains more or less constant throughout the exposure period. Conversely, for a volatile vehicle which begins evaporating from the moment of application, the surface concentration of the chemical increases with time up to the point at which the solvent has disappeared; one is now left with a solid film of the chemical from which continued uptake into the stratum corneum may be very slow and dissolution-limited.
Risk assessment following dermal exposure to volatile vehicles should pay particular attention, therefore, to the duration of contact between the evaporating solvent and the skin (Audra L. Stinchcomb, Fabrice Pirot, Gilles D. Touraille, Annette L. Bunge, and Richard H. Guy, “Chemical uptake into human stratum corneum in vivo from volatile and non-volatile solvents”, Pharmaceutical Research, Vol. 16, No 8, 1999). Kondo et al. studied bioavailability of percutaneous nifedipine in rats from binary (acetone and propylene glycol PG or isopropyl myristate IPM) or ternary (acetone-PG-IPM) solvent systems, compared with the results from simple PG or IPM solvent systems saturated with the drug. (Kondo et al. S, Yamanaka C, Sugimoto I., “Enhancement of transdermal delivery by superfluous thermodynamic potential. III. Percutaneous absorption of nifedipine in rats”, J Pharmaco Biodyn. 1987 December; 10(12):743-9).
U.S. Pat. No. 6,299,900 to Reed et al. discloses a non-occlusive, percutaneous, or transdermal drug delivery system-having active agent, safe and approved sunscreen as penetration enhancer, and optional volatile liquid. The invention describes a transdermal drug delivery system, which comprises at least one physiologically active agent or prodrug thereof and at least one penetration enhancer of low toxicity being a safe skin-tolerant ester sunscreen. The composition comprises an effective amount of at least one physiologically active agent, at least one non-volatile dermal penetration enhancer; and at least one volatile liquid.
U.S. Pat. No. 5,891,462 to Carrara discloses a pharmaceutical formulation in the form of a gel suitable for the transdermal administration of an active agent of the class of estrogens or of progestin class or of a mixture of both, comprising lauryl alcohol, diethylene glycol monoethyl ether and propylene glycol as permeation enhancers.
Mura et al. describe the combination of diethylene glycol monoethyl ether and propylene glycol as a transdermal permeation enhancer composition for clonazepam (Mura P., Faucci M. T., Bramanti G., Corti P., “Evaluation of transcutol as a clonazepam transdermal permeation enhancer from hydrophilic gel formulations”, Eur. J. Pharm. Sci., 2000 February; 9(4): 365-72)
Williams et al. reports the effects of diethylene glycol monoethyl ether (TRANSCUTOL™) in binary co-solvent systems with water on the permeation of a model lipophilic drug across human epidermal and silastic membranes (A. C. Williams, N. A. Megrab and B. W. Barry, “Permeation of oestradiol through human epidermal and silastic membranes from saturated TRANSCUTOL®/water systems”, in Prediction of Percutaneous Penetration, Vol. 4B, 1996). Many references may also illustrate the effect of TRANSCUTOL™ as an intracutaneous drug depot builder well known to one skilled in the art.
U.S. Pat. No. 5,658,587 to Santus et al. discloses transdermal therapeutic systems for the delivery of alpha adrenoceptor blocking agents using a solvent enhancer system comprising diethylene glycol monoethyl ether and propylene glycol.
U.S. Pat. No. 5,662,890 to Punto et al. discloses an alcohol-free cosmetic compositions for artificially tanning the skin containing a combination of diethylene glycol monoethyl ether and dimethyl isosorbide as permeation enhancer.
U.S. Pat. No. 5,932,243 to Fricker et al. discloses a pharmaceutical emulsion or microemulsion preconcentrate for oral administration of macrolide containing a hydrophilic carrier medium consisting of diethylene glycol monoethyl ether, glycofurol, 1,2-propylene glycol, or mixtures thereof.
U.S. Pat. Nos. 6,267,985 and 6,383,471 to Chen et al. disclose pharmaceutical compositions and methods for improved solubilization of triglycerides and improved delivery of therapeutic agents containing diethylene glycol monoethyl ether and propylene glycol as solubilizers of ionizable hydrophobic therapeutic agents.
U.S. Pat. No. 6,426,078 to Bauer et al. discloses an oil-in water microemulsion containing diethylene glycol monoethyl ether or propylene glycol as co-emulsifier of lipophilic vitamins.
Many research experiments have been carried out on diethylene glycol monoethyl ether (marketed under the trademark TRANSCUTOL™ by Gattefossé) as an intracutaneous drug depot builder. For example, Ritschel, W. A., Panchagnula, R., Stemmer, K., Ashraf, M., “Development of an intracutaneous depot for drugs. Binding, drug accumulation and retention studies, and mechanism depot for drugs”, Skin Pharmacol, 1991; 4: 235-245; Panchagnula, R. and Ritschel, W. A., “Development and evaluation of an intracutaneous depot formulation of corticosteroids using TRANSCUTOL® as a cosolvent, in vitro, ex vivo and in-vivo rat studies”, J. Pharm. Pharmacology. 1991; 43: 609-614; Yazdanian, M. and Chen, E., “The effect of diethylene glycol monoethyl ether as a vehicle for topical delivery of ivermectin”, Veternary Research Com. 1995; 19: 309-319; Pavliv, L., Freebern, K., Wilke, T., Chiang, C-C., Shetty, B., Tyle, P., “Topical formulation development of a novel thymidylate synthase inhibitor for the treatment of psoriasis”, Int. J. Pharm., 1994; 105: 227-233; Ritschel, W. A., Hussain, A. S., “In vitro skin permeation of griseofulvin in rat and human skin from an ointment dosage form”, Arzneimeittelforsch/Drug Res. 1988; 38: 1630-1632; Touitou, E., Levi-Schaffer, F., Shaco-Ezra, N., Ben-Yossef, R. and Fabin, B., “Enhanced permeation of theophylline through the skin and its effect on fibroblast proliferation”, Int. J. Pharm., 1991; 70: 159-166; Watkinson, A. C., Hadgraft, J. and Bye, A., “Enhanced permeation of prostaglandin E2 through human skin in vitro”, Int. j. Pharm., 1991; 74: 229-236; Rojas, J., Falson, F., Courraze, G., Francis, A., and Puisieux, F., “Optimization of binary and ternary solvent systems in the percutaneous absorption of morphine base”, STP Pharma Sciences, 1991; 1: 71-75; Ritschel, W. A., Barkhaus, J K., “Use of absorption promoters to increase systemic absorption of coumarin from transdermal drug delivery systems”, Arzneimeittelforsch/Drug Res. 1988; 38: 1774-1777.
Thus there remains a need to provide a pharmaceutically acceptable transdermal or transmucosal pharmaceutical formulation or drug delivery system that exhibits the advantages of both occlusive systems (high thermodynamic activity) and non-occlusive systems (low irritation and sensitization potential, and excellent skin tolerance) while overcoming the disadvantages of these systems such as low skin tolerability and unpleasant odors. The novel transdermal or transmucosal pharmaceutical formulations of the present invention satisfies this need.
SUMMARY OF INVENTIONThe present invention relates to a delivery vehicle for topical pharmaceutical formulations. The delivery vehicle comprises a C2 to C4 alkanol, a polyalcohol, and a monoalkyl ether of diethylene glycol present in relative amounts sufficient to provide permeation enhancement of an active agent through mammalian dermal or mucosal surfaces. Preferably, the delivery vehicle as well as the formulations that contain it are substantially free of long-chain fatty alcohols, long-chain fatty acids and long-chain fatty esters in order to avoid potential undesirable odor and irritation effects caused by such compounds during use of the formulation. These preferred formulations advantageously do not include the undesirable odor-causing and irritation-causing permeation enhancers that were once thought to be necessary for such transdermal or transmucosal formulations. Without these additives, use of the formulations is facilitated and patient compliance is greater.
Certain advantageous delivery system components and amounts are disclosed herein. The alkanol may be selected from the group consisting of ethanol, isopropanol, n-propanol, and mixtures thereof; the polyalcohol from the group consisting of propylene glycol and dipropylene glycol and mixtures thereof; and the monoalkyl ether of diethylene glycol is selected from the group consisting of monomethyl ether of diethylene glycol, monoethyl ether of diethylene glycol, and mixtures thereof. The alkanol is typically present in an amount between about 5 to 80% by weight, the polyalcohol in an amount between about 1% to 30% by weight, and the monoalkyl ether of diethylene glycol in an amount between about 0.2 to 30% by weight so that the delivery vehicle facilitates absorption of the active agent by the dermal or mucosal surfaces so that transfer or removal of the formulation from such surfaces is minimized.
The invention also relates to a non-occlusive formulation comprising a delivery vehicle as disclosed herein along with an active agent or a pharmaceutically acceptable salt thereof present in an amount of between about 1 to 20% by weight of the formulation. Like the deliver system, the formulation is substantially free of long-chain fatty alcohols, long-chain fatty acids, and long-chain fatty esters in order to avoid undesirable odor and irritation effects caused by such compounds during use. As disclosed herein, a wide range of active agents can be delivered by the formulations of the invention.
To facilitate application of the active agent, the formulation may further comprise at least one excipient selected from the group consisting of gelling agents, solvents, cosolvents, antimicrobials, preservatives, antioxidants, buffers, humectants, sequestering agents, moisturizers, emollients, film-forming agents, or permeation enhancers. Thus, the formulation may be provided in the form of a topical gel, lotion, foam, cream, spray, aerosol, ointment, emulsion, microemulsion, nanoemulsion, suspension, liposomal system, lacquer, or non-occlusive dressing.
The invention also relates to a method for administering an active agent to a mammal in need thereof which comprises topically or transdermally administering to the skin or the mucosa of the mammal one of the formulations according to invention as disclosed herein to deliver the active agent to the mammal. Preferably, the active agent is present in an amount of about 0.01 to about 10% of the composition and between about 40 and about 250 mg of the composition is administered daily upon the abdomen, shoulder, arm, or thigh of the mammal to effectuate the treatment.
The features and benefits of the invention will now become more clear from a review of the following detailed description of illustrative embodiments and the accompanying drawings, wherein:
The present invention relates generally to compositions or formulations that contain an active agent for administration to subjects in need thereof. The invention further relates to preferred formulations for the transdermal or transmucosal administration of such agents wherein the formulation is substantially free of malodorous, and irritation-causing permeation enhancers. Surprisingly, the formulations of the present invention can achieve sufficient absorption to result in an effective dosage of the active agent or its metabolites circulating in serum without the inclusion of the malodorous and irritation-causing permeation enhancers that have been used to date. In a preferred aspect of the invention, the formulation is a clear, water-washable, quick-drying, spreadable, non-greasy, non-occlusive topical gel which is free of fatty permeation enhancers.
Advantageously, the substantial omission of the long-chain fatty alcohols, long-chain fatty acids, and long-chain fatty esters provides a formulation that does not have the unpleasant odor, irritation, and/or greasy texture caused by formulations of the prior art that include one or more of such compounds. Thus, the formulation in accordance with the present invention will result in greater patient compliance. The inventive formulations are substantially free of such alcohols, acids, and esters so that the odors associated with those compounds do not emanate from the formulation. In this regard, “substantially free” means an amount which does not impart a perceptible odor to the formulation at a distance of one meter. Such formulations are also deemed to be substantially odor-free. For the purpose of example and illustration, a formulation comprising fatty alcohols, fatty acids and/or fatty esters in an amount of less than about 0.1% by weight of the formulation is substantially odor-free.
It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. As used in this specification, description of specific embodiments of the present invention, and any appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to ““a compound” includes one or more compounds, mixtures of compounds, and the like.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although other methods and materials similar, or equivalent, to those described herein can be used in the practice of the present invention, the preferred materials and methods are described herein.
In describing and claiming the present invention, the following terminology will be used in accordance with the definitions set out below.
The term “dosage form” as used herein refers to a pharmaceutical composition comprising an active agent and optionally containing inactive ingredients, e.g., pharmaceutically acceptable excipients such as suspending agents, surfactants, disintegrants, binders, diluents, lubricants, stabilizers, antioxidants, osmotic agents, colorants, plasticizers, coatings and the like, that may be used to manufacture and deliver active pharmaceutical agents.
The term “gel” as used herein refers to a semi-solid dosage form that contains a gelling agent in, for example, an aqueous, alcoholic, or hydroalcoholic vehicle and the gelling agent imparts a three-dimensional cross-linked matrix (“gellified”) to the vehicle. ? The term “semi-solid” as used herein refers to a heterogeneous system in which one solid phase is dispersed in a second liquid phase.
The term “vehicle” as used herein refers to carrier materials (other than the pharmaceutically active agent) suitable for transdermal administration of a pharmaceutically active agent. A vehicle may comprise, for example, solvents, cosolvents, permeation enhancers, pH buffering agents, antioxidants, gelling agents, additives, or the like, wherein components of the vehicle are nontoxic and do not interact with other components of the total composition in a deleterious manner.
The phrase “non-occlusive, transdermal drug delivery” as used herein refers to transdermal delivery methods or systems that do not occlude the skin or mucosal surface from contact with the atmosphere by structural means, for example, by use of a patch device, a fixed application chamber or reservoir, a backing layer (for example, a structural component of a device that provides a device with flexibility, drape, or occlusivity), a tape or bandage, or the like that remains on the skin or mucosal surface for a prolonged period of time. Non-occlusive, transdermal drug delivery includes delivery of a drug to skin or mucosal surface using a topical medium, for example, creams, ointments, sprays, solutions, lotions, gels, and foams. Typically, non-occlusive, transdermal drug delivery involves application of the drug (in a topical medium) to skin or mucosal surface, wherein the skin or mucosal surface to which the drug is applied is left open to the atmosphere.
The term “transdermal” delivery, as used herein refers to both transdermal (and “percutaneous”) and transmucosal administration, that is, systemic delivery by passage of a drug through a skin or a mucosal tissue surface and ultimately into the bloodstream.
The term “topical” delivery, as used herein refers to local delivery of a drug into a skin surface or a mucosal tissue surface with minimal passage into the bloodstream.
The phrase “therapeutically effective amount” as used herein refers to a nontoxic but sufficient amount of a drug, agent, or compound to provide a desired therapeutic effect
In accordance with the invention, the delivery vehicle of the present invention preferably comprises a C2 to C4 short-chain alkanol, a polyalcohol, and a monoalkyl ether of diethylene glycol in an amount sufficient to provide permeation enhancement of the oxybutynin through mammalian dermal or mucosal surfaces. For the purpose of illustration and not limitation, the alkanol may be ethanol, isopropanol, or n-propanol. The alkanol is preferably ethanol. The alkanol is present in an amount between about 45 to 75% w/w, preferably between about 50% to 70%, and more preferably between about 55% and 65% w/w. As known in the art, the amount of the alkanol may be selected to maximize the diffusion of the active agent through the skin while minimizing any negative impact on the active agent itself or desirable properties of the formulation. The alkanol can be present in a mixture with water.
The polyalcohol is preferably propylene glycol or dipropylene glycol. The polyalcohol may also be a polyethylene glycol having general formula CH2OH(CH2OH)nCH2OH wherein the number of oxyethylene groups represented by n is between 4 to 200, propylene glycol, dipropylene glycol, butylene glycol, hexylene glycol, and mixtures thereof. The polyalcohol is advantageously present in an amount between about 1% and 30% of the vehicle, preferably from 2.5% to 20% w/w, and more preferably from about 5% to 10% w/w.
The monoalkyl ether of diethylene glycol is preferably selected from the group consisting of monomethyl ether of diethylene glycol, monoethyl ether of diethylene glycol, and mixtures thereof. It is present in an amount of about 1% and 15%, preferably between about 2.5% to 10% w/w and more preferably between about 2.5% to 5% w/w.
The formulation may further include a thickening agent or gelling agent present in an amount sufficient to alter the viscosity of the formulation. A gelling agent can be selected from the group including: carbomer 980 or 940 NF, 981 or 941 NF, 1382 or 1342 NF, 5984 or 934 NF, ETD 2020, 2050, 934P NF, 971P NF, 974P NF, Noveon AA-1 USP; cellulose derivatives such as ethylcellulose, hydroxypropylmethylcellulose (HPMC), ethylhydroxyethylcellulose (EHEC), carboxymethylcellulose (CMC), hydroxypropylcellulose (HPC) (Klucel grades), hydroxyethylcellulose (HEC) (Natrosol grades), HPMCP 55, Methocel grades; natural gums such as arabic, xanthan, guar gums, alginates; polyvinylpyrrolidone derivatives such as Kollidon grades; polyoxyethylene polyoxypropylene copolymers such as Lutrol F grades 68, 127. Other gelling agents include chitosan, polyvinyl alcohols, pectins, veegum grades. A tertiary amine, such as triethanolamine or trolamine, can be included to thicken and neutralize the system. The amount and the type of the gelling agent in the formulation may be selected by the man skilled in the art to provide the desired product consistency and/or viscosity to facilitate application to the skin. The gelling agent is present from about 0.2 to about 30% w/w of the formulation depending on the type of polymer. For example, the gelling agent is preferably present in an amount between about 0.3% to 2% for carbomers, and between about 1% to 5% for hydroxypropylcellulose derivatives.
In preferred embodiments, as noted, the composition is non occlusive. The penetration enhancing system of the present invention can also be used for mucosal delivery through the buccal, sublingual, auricular, nasal, ophthalmic, rectal, or vaginal mucosa.
The formulation may further include preservatives such as, but not limited to, benzalkonium chloride and derivatives, benzoic acid, benzyl alcohol and derivatives, bronopol, parabens, centrimide, chlorhexidine, cresol and derivatives, imidurea, phenol, phenoxyethanol, phenylethyl alcohol, phenylmercuric salts, thimerosal, sorbic acid, derivatives thereof and the like. The preservative is present from about 0.01 to about 10% w/w depending on the type of compound.
The formulation may further include antioxidants such as but not limited to, tocopherol, ascorbic acid, butylated hydroxyanisole, butylated hydroxytoluene, fumaric acid, malic acid, propyl gallate, sulfites, derivatives thereof and the like. The antioxidant is present from about 0.001 to about 5.0% w/w of the formulation depending on the type of compound.
The formulation may further include a buffer such as carbonate buffers, citrate buffers, phosphate buffers, acetate buffers, hydrochloric acid, lactic acid, tartric acid, diethylamine, triethylamine, diisopropylamine, aminomethylamine. Although other buffers as known in the art may be included. The buffer may replace up to 100% of the water amount within the formulation.
The formulation may further include a humectant. The formulation may further include humectant, such as but not limited to glycerin, propylene, glycol, sorbitol, triacetin. The humectant is present from about 1 to 10% w/w of the formulation depending on the type of compound.
The formulation may further include a sequestering agent such as edetic acid. The sequestering agent is present from about 0.001 to about 5% w/w of the formulation depending on the type of compound.
The formulation may further include anionic, non-ionic or cationic surfactants. The surfactant is present from about 0.1% to about 30% w/w of the formulation depending on the type of compound.
The formulation may further include a pH regulator, generally, a neutralizing agent, which can optionally have cross-linking function. By way of example and not limitation, the pH regulator may include a ternary amine such as monoethanolamine, diethanolamine, triethanolamine, tromethamine, tetrahydroxypropylethylendiamine, aminomethyl propanol, diisopropanolamine, or an inorganic alkali such as NaOH solution, KOH solution, or NH4OH solution. The pH regulator is present in the formulations in variable amounts depending on the nature and the relative strength of the pH regulator. The optimum pH may also be determined and may depend on, for example, the nature of the active agent and the degree of flux required.
For some lesser preferred embodiments, the delivery vehicle may contain a saturated fatty alcohol or fatty acid, or mixtures thereof in an amount of from about 0.4 to 10%, wherein the fatty alcohol or fatty acid have the formula CH3—(CH2)n—CH2OH or CH3—(CH2)n—H2COOH, respectively, in which n is an integer from 8 to 22; or an unsaturated fatty alcohol or fatty acid, or mixtures thereof, wherein said unsaturated fatty alcohol and/or fatty acid have the formula CH3—(CnH2(n-x))—OH or CH3—(CnH2(n-x))—COOH, respectively, in which n is an integer from 8 to 22. Of these, lauryl alcohol or myristyl alcohol present in an amount from 0.5 to 2% by weight of the total formulation can be used.
Further, it has also been found that the glycol acts as a modulator of the capability of the monoalkyl ether of diethylene glycol to build a drug depot within the different layers of the skin. Also, the significant reduction of unabsorbed active drug(s) remaining at the application surface area results from the simultaneous although independent inhibition of crystallization and transdermal drug penetration, enhanced or not by additional permeation enhancer(s).
Additional advantages of the present invention include the discovery that the association of a monoalkyl ether of diethylene glycol and the preferred propylene glycol component at specified ratios exhibits a synergic effect and inhibits crystallization of the active ingredient(s) in transdermal semi-solid formulations. In addition, it has been discovered that a totally unexpected control of the active drug(s) distribution in the different layers of the skin is achieved when modifying the range of the monoalkyl ether:glycol ratio, simultaneously but independently from the crystallization inhibitor effect above mentioned.
The monoalkyl ether of diethylene glycol and the glycol are generally present in a weight ratio of 10:1 to 1:10 and preferably in a ratio ranging from 10:1 to 2:1 or 1:2 to 1:10, although ratios between 3:1 and 1:1 or 2:1 to 1:1 are preferred.
It has been surprisingly discovered that it is possible to achieve a therapeutically effective, sustained and controlled penetration rate of diverse active substances into the skin with the aid of the inventive delivery system. It has also been discovered surprisingly that the formulations compositions disclosed herein exert higher permeation rates when compared with compositions that do not contain the delivery system of the invention.
It also has been surprisingly discovered also that by utilizing the combination of diethylene glycol monoethyl ether and propylene glycol as permeation enhancers in the delivery system of the invention herein disclosed, an adequate penetration enhancement factor and a sustained flux of the active agent is attained, thereafter reflected in achieving therapeutic effective, controlled and sustained levels of the active drugs by only once-a-day application of the formulation. Thus, the present invention relates to a method for administering topically or systemically different active substance(s).
The delivery vehicle may further include moisturizers and emollients to soften and smoothen the skin or to hold and retain moisture. By way of example and not limitation, moisturizers and emollients may include cholesterol, lecithin, light mineral oil, petrolatum, and urea.
The present formulations advantageously (a) inhibits crystallization of the at least one active ingredient on a skin or mucosal surface of a mammal, (b) reduces or prevents transfer of the formulation to clothing or to another being, (c) modulates biodistribution of the at least one active agent within different layers of skin, (d) facilitates absorption of the at least one active agent by a skin or a mucosal surface of a mammal, or (e) provides a combination of one or more of (a) through (d).
For any particular formulation, the active agent, delivery vehicle and other ingredients may be selected to achieve the desired drug delivery profile and the desired penetration.
In accordance with the invention, the active agent may be present in an amount between about 0.1% to 20% by weight of the delivery vehicle. The active agent may be present in the form of a pharmaceutically acceptable salt thereof. Examples of such salts comprise, but are not limited to, acetate, bitartrate, citrate, edetate, edisylate, estolate, esylate, fumarate, gluceptate, gluconate, glutamate, hydrobromide, hydrochloride, lactate, malate, maleate, mandelate, mesylate, methylnitrate, mucate, napsylate, nitrate, pamoate, pantothenate, phosphate, salicylate, stearate, succinate, sulfate, tannate and tartrate. The invention is applicable to combinations of active agents, where a primary active agent is present in combination with a secondary active agent for concurrent administration to the subject.
The active agent may be a hormone selected from the group consisting of an androgen, estrogen, progestin, or a combination thereof. The androgen may be selected from the group consisting of testosterone, 17-β-hydroxyandrostenone, testosterone esters, methyl testosterone, testolactone, oxymetholone, fluoxymesterone, androsterone, androsterone acetate, androsterone propionate, androsterone benzoate, androstenediol, androstenediol-3-acetate, androstenediol-17-acetate, androstenediol-3,17-diacetate, androstenediol-17-benzoate, androstenediol-3-acetate-17-benzoate, androstenedione, sodium dehydroepiandrosterone sulfate, 4-dihydrotestosterone, 5 adihydrotestosterone, dromostanolone, dromostanolone propionate, ethylestrenol, nandrolone phenpropionate, nandrolone decanoate, nandrolone furylpropionate, nandrolone cyclohexanepropionate, nandrolone benzoate, nandrolone cyclohexanecarboxylate, oxandrolone, and stanozolol or any combination thereof. The estrogen may be selected from the group consisting of 17 beta-estradiol, estradiol, estradiol benzoate, estradiol 17 beta-cypionate, estriol, estrone, ethynil estradiol, mestranol, moxestrol, mytatrienediol, polyestradiol phosphate, quinestradiol, and quinestrol or any combination thereof. The progestin may be selected from the group consisting of allylestrenol, anagestone, chlormadinone acetate, delmadinone acetate, demegestone, desogestrel, dimethisterone, dydrogesterone, ethynilestrenol, ethisterone, ethynodiol, ethynodiol diacetate, fluorogestone acetate, gestodene, gestonorone caproate, haloprogesterone, 17-hydroxy-16-methylene-progesterone, 17 alpha-hydroxyprogesterone, 17 alpha-hydroxygesterone caproate, lynestrenol, medrogestone, medroxyprogesterone, megestrol acetate, melengestrol, 16-methylene-17-alpha-acetoxy-19-nor-pregn-4-ene,3,20-dione, norethindrone, norethindrone acetate, norethynodrel, norgesterone, norgestimate, norgestrel, norgestrienone, 19-norprogesterone, norvinisterone, pentagestrone, progesterone, natural progesterone, promegestone, quingestrone, and trengestone or any combination thereof. Preferably, the combination of estrogen and progestin is not present in the formulation.
The active agent may also be any of the following: drugs to treat Parkinson disease; drugs to treat Alzheimer disease and senile dementia; Attention Deficit and Hyperactivity Disorders (ADHD) drugs; drugs to treat narcolepsy; anti-anxiety drugs; anti-depression drugs; drugs to treat epilepsy; drugs to treat insomnia; drugs to treat motor neurone diseases; drugs to treat multiple sclerosis; anti-nausea and anti-vomiting drugs; anti-psychotic drugs; hypnotics; anti-depressants; tranquilizers; drugs to treat Restless Legs Syndrome (RLS); drugs to treat alcohol addiction, nicotine addiction, drug addiction, or food addiction; central analgesics; drugs to treat central metabolism disorders; or a combination of one of the previously mentioned drugs with another drug.
The active agent may also be an anti-Parkinson drug selected from the group consisting of amantadine, benserazide, carbidopa, levodopa, benztropine, biperiden, benzhexyl, procyclidine, bornaprine, budipine, entacapone, ethopropazine, lazabemide, memantine, orphenadrine, selegiline, tolcapone, trihexyphenidyl, modafinil, talampanel, altinicline, brasofensine, safinamide, droxidopa, rasagline, bromocriptine, cabergoline, pergolide, piribedil, pramipexole, quinagolide, terguride, rotigotine, riluzole, talipexole, piroheptine, bifeprunox, spheramine, lisuride, sumanirole, ropinirole, rotigotine, and pharmaceutically acceptable salts, isomers, and mixtures thereof; an anti-Alzheimer drug selected from the group consisting of tacrine, donepezil, rivastigmine, galantamine, amantadine, memantine, rimantadine, and pharmaceutically acceptable salts, isomers, and mixtures thereof; or an analgesic drug selected from the group consisting of alfentanil, buprenorphine, butorphanol, codeine, dextromoramide, dextropropoxyphene, dezocine, diamorphine, dihydrocodeine, fentanyl, flupirtine, hydrocodone, hydromorphone, ketobemidone, levomethadyl, mepiridine, meptazinol, methadone, morphine, nalbuphine, oxycodone, oxymorphone, papavereturn, pentazocine, pethidine, phenoperidine, piritramide, remifentanil, tilidine, tramadol, sufentanil and pharmaceutically acceptable salts, isomers, and mixtures thereof.
The active agent may also be an anti-addiction drug selected from the group consisting of nicotine, buprenorphine, naloxone, and pharmaceutically acceptable salts, isomers, and mixtures thereof; or an anti-psychotic drug selected from the group consisting of chlorpromazine, fluphenazine, perphenazine, prochlorperazine, thioridazine, trifluoperazine, butyrophenones, haloperidol, droperidol, pimozide, clozapine, olanzapine, mirtanzapine, tinaeptine, bupropion, risperidone, quetiapine, ziprasidone, amisulpride, melperone, paliperidone, aripiprazole, and pharmaceutically acceptable salts, isomers, and mixtures thereof; or an anti-anxiety drug selected from the group consisting of alprazolam, bromazepam, diazepam, lorazepam, clonazepam, temazepam, oxazepam, flunitrazepam, triazolam, chlordiazepoxide, flurazepam, estazolam, nitrazepam, and pharmaceutically acceptable salts, isomers, and mixtures thereof; or even an anti-depressant drug selected from the group consisting of citalopram, escitalopram oxalate, fluoxetine, fluvoxamine, paroxetine, sertraline, dapoxetine; venlafaxine and duloxetine; harmaline, iproniazid, isocarboxazid, nialamide, pargyline, phenelzine, selegiline, toloxatone, tranylcypromine, brofaromine, moclobemide; amitriptyline, amoxapine, butriptyline, clomipramine, desipramine, dibenzepin, dothiepin, doxepin, imipramine, iprindole, lofepramine, melitracen, nortriptyline, opipramol, protriptyline, trimipramine; maprotiline, mianserin, nefazodone, trazodone, and pharmaceutically acceptable salts, isomers, and mixtures thereof.
The active agent may also be a drug for treating ADHD selected from the group consisting of methylphenidate, and pharmaceutically acceptable salts, isomers, and mixtures thereof; or an anti-insomnia drug selected from the group consisting of zolpidem, zopiclone, and pharmaceutically acceptable salts, isomers, and mixtures thereof; or a 5-alpha-reductase inhibitor such as the azasteroid compounds, namely, finasteride or dutasteride.
Also in accordance with the invention, the pharmaceutical active agent may include anti-gout drugs such as colchicine and derivatives, sulfinpyrazone, probenecid, benzbromarone, allopurinol; local anaesthetics such as benzocaine, procaine, tetracaine, lidocaine, etidocaine, prilocalne, mepivacaine, bupivacaine, butanilicaine, articaine, fomocaine; general anaesthetics such as methohexital, thiamylal, thiopenthal, ketamine, etomidate, propofol, midazolam, flumazenil, droperidol, fentanyl, alfentanil, sufentanil; muscle relaxant drugs such as curare derivatives, hexacarbacholine, dantrolene, tetrazepam, carisoprodol, chlorzoxazone, baclofen, memantine, tizandine; diuretics such as hydrochlorothiazide and derivatives, chlortalidone, indapamide, furosemide, bumetanide, piretanide, azosemide, etozolin, ethacrynic acid, amiloride, triamterene, spironolactone; angiotensin converting enzyme inhibitors such as captopril, enalapril, trandolapril, lisinopril, perindopril, benazepril, cilazepril, fosinopril, moexipril, quinapril, ramipril; calcium-channel blockers such as bepridil, diltiazem, felodipine, flunarizine, isradipine, nicardipine, nitrendipine, nifedipine, nimodipine, verapamil, amlodipine, lacidipine, buflomedil; anti-arythmics such as quinidine, ajmaline, procainamide, disopyramide, propafenone, tocamide, phenyloin, aprindine, mexiletine, flecamide, lorcamide, propafenone, sotalol, amiodarone, verapamil, diltiazem; anti-angina drugs such as nitrate derivatives, molsidomine; anti-migraine drugs such as, pizotifene, oxetorone, methysergide sumatriptan, zolmitriptan, naratriptan, eletriptan, almotriptan, rizatriptan; antiemetic drugs such as chlorphenoxamine, dimenhydramine, meclozine, triethylperazine, triflupromazine, metoclopramide, bromopride, domperidone, granisetron, ondansetron, tropisetron, dolasetron, alosteron, tegaserod; anti-histaminic and anti-asthma drugs such as cromoglycate, nedocromil, tritoqualine, ketotifene, lodoxamide, salbutamol, terbutaline, pirbuterol, salmeterol, formoterol, bambuterol, montelukast, pranlukast, theophylline, ipratropium, oxitropium, beclometasone, dexamethasone, fluticasone, budesonide, flunisolide; thrombolytics such as alteplase and derivatives, streptokinase, urokinase; analgesics such as morphine, codeine, diamorphine, dihydrocodeine, hydromorphone, hydrocodone, oxycodone, oxymorphone, levorphanol, pethidine, levomethadone, fenpipramine, piritramide, clofedanol, pentazocine, buprenorphine, butorphanol, nalbuphine, tilidine, tramadol, nefopam, salicylic acid and derivatives, salsalate, diflunisal, acetaminophen, benorylate, mefenamic acid, flufenamic acid, niflumic acid, metamizole, phenazone, phenylbutyazone, aminophenazone, oxyphenbutazone, azapropazone, indometacin, diclofenac, sulindac, felbinac, ibuprofen, naproxen, fenoprofen, flurbiprofen, ketoprofen, tiaprofenic acid, nabumetone, piroxicam, tenoxicam, meloxicam, antitussive agents such as codeine and derivatives, clobutinol, isoaminile, pentoxyverine, butamirate, oxeladine, pipazetate; tricyclic antidepressants such as imipramine, desipramine, trimipramine, lofepramine, clomipramine, opipramol, amitriptyline, amitriptylinoxide, nortriptyline, dibenzepin, doxepin, melitracen; tetracyclic antidepressants such as maprotiline, mianserin; atypical antidepressants such as fluvoxamine, trazodone, viloxacin, fluoxetine; monoamine oxidase inhibitors such as tranylcipromine; serotonin precursors such as oxitriptan; lithium salts; tranquilizers such as meprobamate, hydroxyzine, chlordiazepoxide, temazepam, flurazepam, lormetazepam, nitrazepam, flunitrazepam, diazepam, prazepam, oxazepam, lorazepam, clonazepam, bromazepam, clotiazepam, alprazolam, triazolam, oxazolam, midazolam, ketazolam, brotizolam, clobazam, clorazepate, buspirone; amphetamines and related compounds such as amfetamine, metamfetamine, fenetylline, methylphenidate, prolintane; anorectics such as cathine, amfepramone, mefenorex, propylhexedrine, fenfluramine; psychodysleptics such as N-dimethyltryptamine, psilocin, psilocybin, bufotenin, lysergide, mescaline, tetrahydrocannabinol; nootropics such as pyritinol, piracetam, meclofenoxate; hypnotics such as carbromal, bromisoval, vinylbital, aprobarbital, secbutabarbital, pentobarbital, cyclobarbital, phenobarbital, glutethimide, methyprylon, methaqualone; analeptics such as doxapram; tricyclic neuroleptics such as chlorpromazine, promazine, triflupromazine, alimemazine, levomepromazine, chlorprothixene, pecazine, thioridazine, perphenazine, trifluoperazine periciazine, perazine, fluphenazine, dixyrazine, clopenthixol, dixyrazine, prothipendyl, thithixene, chlorprothixene, clopenthixol, flupentixol; butyrophenones and diphenylbutylpiperidines neuroleptics such as haloperidol, bromperidol, droperidol, trifluperidol, pipamperone, melperone, benperidol, pimozide, fluspirilene; benzamide neuroleptics such as sulpiride; anti-psychotic drugs such as clozapine, haloperidol, olanzapine, quetiapine, risperidone; anti-convulsive drugs such as carbamazepine, valproic acid and its derivatives, primidone, phenyloin, ethosuximide, trimethadione, sultiame, hypothalamo-hypophysis regulators such as gonadoreline, triptoreline, leupropreline, busereline, gosereline, nafareline, gonadotrophins, follitropins, danazol, clomifene, quinagoline, bromocriptine, lisuride; anti hypo- and anti hyperthyroidy drugs such as thyreotropin releasing hormone, thyreostimuline hormone, triiodothyronine, thyroxine, tiratricol, benzylthiouracile, clotrimazole, corticosteroids; glucocorticoids and mineralocorticoids; glycemia regulators such as insuline, glipizide, glibenclamide, glibornuride, gliclazide, carbutamide, glimepiride, repaglinide, metformine, acarbose, miglitol, glucagon, diazoxide; hypolipidemia drugs such as orlistat, simvastatine, pravastatine, fluvastatine, atorvastatine, tiadenol, cholestyramine, fenofibrate, ciprofibrate, bezafibrate, gemfibrozil, ursodiol; phosphocalcic metabolism regulators such as ergocalciferol, cholecalciferol calcitriol, alfacalcidol, calcifediol, calcipotriol, tacalcitol; anti-inflammatory drugs such as nabumetone, meloxicam, nimesulide, etodolac, alminoprofene, sulfasalazine, mefasalazine, olsalazine, rofecoxib, celecoxib, valdecoxib, nefopam; antisecretive gastric drugs such as omeprazole, lansoprazole, pantoprazole, rabeprazole, misoprostol; laxatives; gastric mucosa protectors such as cimetidine, famotidine, ranitidine, nizatidine, gastric motricity modulators; bile salts adsorbants; chelators; gall stone dissolvants; anti-anemia drugs; cutaneous diseases drugs; alpha antagonist drugs such as urapidil and derivatives, prazosine and derivatives, nicergoline, moxisylyte, anti parasitic drugs such as albendazole, atovaquone, chloroquine, dehydroemetine, diloxanide, furazolidone, halofantrine, iodoquinol, ivermectin, mebendazole, mefloquine, metronidazole, nifurtimox, primaquine, pyrantel, pyrimethamine, quinine, quinidine, penicillins; cephalosporins; aminosids; polypeptides; sulfamides; diaminopyrimidines; tetracyclins; chloramphenicol; thiamphenicol; macrolides; vancomycin; teicoplanin; rifampicin; fusidic acid; 5-nitro-imidazoles; lincosamides; quinolones; isoniazide, ethambutol; antineoplasic drugs such as chlormethine, chlorambucil, melphalan, cyclophosphamide, ifosfamide, estramustine, carnustine, lomustine, fotemustine, carbazine derivatives, cisplatine and derivatives, thiothepa, daunorubicine and derivatives, mitoxantrone, 5-fluorouracil, capecitabine, cytarabine, gemcitabine, mercaptiopurine azathioprine, fludarabine, thioguanine, pentostatine, cladribine, raltitrexed; anti virus drugs such as zidovudine and derivatives, aciclovir and derivatives, foscarnet, ritonavir and derivatives; antifungus drugs such as nystatine, terbinafine, micanazole, ketoconazole, fluconazole, itraconazole, bifonazole, econazole, omoconazole, sulconazole, tioconazole, isoconazole, fenticonazole, sertaconazole.
The active agent may also be oxybutynin or another anticholinergic drug. Although oxybutynin is the preferred anti-cholinergic agent that is disclosed herein, other such agents, among which those having an antimuscarinic activity are preferred, can be used in place of oxybutynin. Preferred anti-cholinergic drugs with antimuscarinic activity include, without limitation, tolterodine, trospium, propiverine, flavoxate, emepronium, propantheline, darifenacin, and solifenacin. These can be used, for example, in the treatment of hyperactivity of the detrusor muscle (over activity of the bladder muscle) with frequent urge to urinate, increased urination during the night, urgent urination, involuntary urination with or without the urge to urinate (incontinence), painful or difficult urination.
Preferably, the formulations of the invention provides therapeutic levels of the active agent or metabolite for at least 24 hours. More preferably, the method provides sustained therapeutic levels for at least 48 hours. Most preferably, the method provides sustained therapeutic levels for at least 72 hours. Thus, the formulations of the invention only need to be administrated every once a day, every other day, every third day or twice per week.
The present invention further provides various treatment methods for administering the active agent to a subject in need thereof via the topical or transdermal formulations disclosed herein. For example, methods for treating hormonal diseases, disorders, or conditions in a subject are disclosed. These methods generally comprise administering to the subject a formulation comprising an effective dosage of at least one active agent of a hormone and the delivery vehicle.
The subject in need of treatment may be male or female. Thus, the type of active agents selected for the formulation and method of treatment, and the effective dosages of the active agents is in part dependent on the sex of the subject to be treated, and the type of hormonal disorder being treated.
For the purpose of illustration and not limitation, and in accordance with the invention, for example, a woman undergoing treatment may be of childbearing age or older, in whom ovarian estrogen, progesterone and/or androgen production has been interrupted either because of natural menopause, surgical procedures, radiation, chemical ovarian ablation or extirpation, or premature ovarian failure. In addition to natural menopause and aging, a decline in total circulating androgens leading to testosterone deficiency can be attributed to conditions that suppress adrenal androgen secretion (i.e., acute stress, anorexia nervosa, Cushing's syndrome, and pituitary renal insufficiency), conditions that can decrease ovarian androgen secretion (i.e., ovarian failure and the use of pharmacologic doses of glucocorticoids), and chronic illness such as muscle-wasting diseases like Acquired Immune Deficiency Syndrome (AIDS). Thus, the term “hormonal disorder” as used herein means any condition that causes a suppression or reduction of hormonal secretions in a subject.
In addition to treating female subjects for female menopausal symptoms due to aging and other factors as discussed above, reduced levels of androgens (and estrogens) in women may lead to female sexual dysfunction (FSD) resulting in clinical symptoms such as lack of sex drive, arousal or pleasure; low energy, reduced sense of well-being and osteoporosis. Preferred results of using the formulations of the invention to treat FSD in women may include one or more of the following: increased energy, increased sense of well-being, decreased loss of calcium from bone, and increased sexual activity and desires.
In pre-menopausal women, total plasma testosterone concentrations generally range from 15-65 ng/dL (free testosterone in pre-menopausal women is approximately 1.5 to 7 pg/ml) and fluctuate during the menstrual cycle, with peaks of androgen concentration corresponding to those of plasma estrogens at the pre-ovulatory and luteal phases of the cycle. In the years leading to postmenopausal transition, levels of circulating androgens begin to decline as a result of age-related reductions of both ovarian and adrenal secretion. There are reports in studies that 24-hour mean plasma testosterone levels in normal pre-menopausal women in their 40's are half that of women in their early 20's. It has been generally accepted, however, that women with androgen deficiency have total testosterone levels <25 ng/dL (<50-years-old) or <20 ng/dL (≧50-years-old) while oophorectomized women can have total testosterone levels <10 ng/dL.
In this regard, the method may include administering to the female subject a therapeutically effective dosage of testosterone from about 1 mg to about 3 mg each 24 hours. Therefore, the formulation preferably provides the subject with a total serum concentration of testosterone from at least about (>30 ng/dL) 15 to about 55 ng/dL, or a free serum concentration of testosterone from about 2 to about 7 pg/mL.
Moreover, studies have shown that testosterone replacement combined with estrogen replacement therapy (“ERT”) improves parameters of sexual function and well-being versus ERT alone. A decline in rates of sexual intercourse and fewer sexual thoughts and fantasies has been associated with significant decreases in estradiol and testosterone. A decrease in testosterone has also been associated with decreased frequency of coitus. Although estradiol treatment alone in oophorectomized women improved vasomotor symptoms, vaginal dryness, and general well-being, little improvement in libido has been observed. Increased sexual drive, arousal, and frequency of sexual fantasies were observed in hysterectomized and oophorectomized women with testosterone-enanthate injections over and above those observed with ERT alone. Therefore, in accordance with the method of the invention, treating female subjects comprising administration of formulations comprising active agents including both an androgen, preferably testosterone, and an estrogen, as well as treating female subjects comprising administering formulations comprising estradiol alone as the active agent.
Another study in women who were naturally or surgically menopausal with inadequate ERT for ≧4 months showed significant improvements in sexual sensation and desire after 4 and 8 weeks of androgen/estrogen treatment vs. placebo or estrogen treatment alone. Sexual desire, arousal, well-being, and energy levels were enhanced with androgen/estrogen therapy in studies in surgically menopausal women. Results of improved libido with subcutaneous testosterone implants in combination with subcutaneous estrogen implants in postmenopausal women have also been reported. In women who have undergone oophorectomy and hysterectomy, transdermal testosterone improved sexual function and psychological well-being. To achieve good response in terms of libido, plasma testosterone levels need to be restored to near the upper end of the normal physiologic range observed in young ovulating women.
Therefore, treatment with a separate or the same composition including estrogen may be desirable to achieve at least the preferred results described above. A pre-menopausal female subject generally has a serum concentration of estradiol from about 30 to 100 pg/mL, whereas normal post-menopausal levels are below 20 pg/mL.
Further, reduced levels of estrogens (and progestin) in women, such as due to aging, leads to menopause resulting in clinical symptoms such as hot flashes and night sweats, vaginal atrophy, decreased libido, increased risk of heart disease and osteoporosis. Preferred results of using a composition of the present invention may include one or more of the following: decreased incidence and severity of hot flashes and night sweats, decreased loss of calcium from bone, decreased risk of death from ischemic heart disease, increased vascularity and health of the vaginal mucosa and urinary tract are and increased sexual activity and desires. Thus, in another preferred embodiment, the method include administering to a female subject in need of treatment, a formulation comprising both an estrogen in combination with a progestin as active agents.
As stated above, the methods include treating male subjects for hormonal disorders. For example, the male is treated for hypogonadism (low testosterone levels). Hypogonadism in men may result in clinical symptoms including impotence, lack of sex drive, muscle weakness and osteoporosis. Preferred results of using the compositions of the invention to treat hypogonadism in men may include one or more of the following: decreased incidence and severity of impotence, decreased loss of calcium from bone, increased muscle strength, and increased sexual activity and desires.
A normal male subject generally has a total serum concentration of testosterone from about 300 to 1050 ng/dL, whereas hypogonadal men have levels below 300 ng/dL. Therefore, the composition of the invention may be used to provide the subject with a therapeutically effective dosage of testosterone of about 50 mg/day. Therefore, in use the composition preferably provides the subject with a free serum concentration of testosterone from at least about 300 to 1000 ng/dL.
The invention also relates to a method for administering oxybutynin or other anticholinergic agent to a mammal in need thereof comprising topically or transdermally administering to the skin or the mucosa of a mammal one of the compositions disclosed herein. Preferably, the mammal is a human. For example, the treatments methods include treating hyperactivity of the detrusor muscle with frequent urge to urinate, increased urination during the night, urgent urination, involuntary urination with or without the urge to urinate, painful or difficult urination, detrusor hyperreflexia and detrusor instability. Typically, not more than 200 mg of the active agent is administered per day, with a daily dose of between about 40 and about 100 mg being preferred. The composition is advantageously administered upon the abdomen, shoulder, arm, or thigh of the subject.
The preferred formulations for these treatments include the following:
The preferred formulations of the present invention are advantageous at least for the following reasons. First, the formulations of the present invention are substantially free of long-chain fatty alcohols, long-chain fatty acids, and long-chain fatty esters. Surprisingly, the formulations exhibit skin penetration sufficient to deliver an effective dosage of the active agent to the user. This is an unexpected advantage that those of ordinary skill in the art would not have readily discovered since it had been generally understood that permeation enhancers, and more particularly long-chain fatty alcohols, long-chain fatty acids, and long chain fatty esters, would be required to enhance skin penetration of certain active agents such as oxybutynin to permit an effective dose to penetrate the skin. Second, because the formulation does not include aliphatic acid groups, such as fatty acids, that are commonly included in topical gels, it does not have the odor or oily texture which is associated with that ingredient as in presently-available gels. Numerous studies acknowledge the irritation-causing potential of unsaturated fatty acids such as oleic acid. See, Tanojo H. Boelsma E, Junginger H E, Ponec M, Bodde H E, “In vivo human skin barrier modulation by topical application of fatty acids,” Skin Pharmacol Appl. Skin Physiol. 1998 March April; 11 (2) 87 97. Third, the absence of long-chain fatty alcohols, long-chain fatty acids, and long-chain fatty esters means that the irritation potential is lower and that there is less chance for the components to interact, reducing the need for stabilizers in the formulation. It is to be understood, however, that if such stabilizers are desired, the invention encompasses formulations which include antioxidants, chelators or preservatives. The reduction in the number of ingredients is advantageous at least in reducing manufacturing costs, possible skin irritation.
Additionally, the reduced number of ingredients increases the storage stability of the formulation by decreasing the chance that the ingredients will interact prior to being delivered to the patient in need thereof. This does not, however, imply that additional ingredients cannot be included in the formulation for particular aesthetic and/or functional effects. For example, the formulation may optionally include one or more moisturizers for hydrating the skin or emollients for softening and smoothing the skin. Glycerin is an example of such a suitable moisturizing additive.
The formulation may be applied once daily, or multiple times per day depending upon the condition of the patient. The formulation of the invention may be applied topically to any body part, such as the thigh, abdomen, shoulder, and upper arm. In one embodiment, up to 10 grams of a formulation in the form of a gel is applied to an area of skin. In a preferred embodiment of the invention, not more than 5 grams of a formulation in the form of a gel is applied to about an area of skin for about 1 g of gel. In a most preferred embodiment of the invention, about 1 to 3 grams of a formulation in the form of a gel is applied to about a 100 square-centimeter to a 1000 square-centimeter area of skin. Formulation of the present invention may be applied on alternate areas of the body as applications alternate. For example, the gel may be applied to the abdomen for the first application, the upper arm for the second application, and back to the abdomen for the third application. This may be advantageous in alleviating any sensitivity of the skin to repeated exposure to components of the formulation. Alternatively, the formulation of the present invention may be applied always on the same area of the body.
The invention includes the use of the formulations described above to treat subjects to increase circulating levels of the active agent or a metabolite thereof within the patient. Preferred dosage units are capable of delivering an effective amount of the active agent or metabolite over a period of about 24 hours. By an “effective” or “therapeutically effective” amount of the active agent or metabolite means a nontoxic, but sufficient amount to provide the desired effect. However, it will be appreciated by those skilled in the art that the desired dose will depend on the specific form of the active agent or metabolite as well as on other factors. The formulation is preferably applied on a regularly-timed basis so that administration of the active agent or metabolite is substantially continuous.
The composition may be applied directly or indirectly to the skin or mucosal surfaces. Preferably, the composition is non occlusive. The phrase “non-occlusive” as used herein refers to a system that does not trap nor segregate the skin from the atmosphere.
The composition of the invention can be in a variety of forms suitable for transdermal or transmucosal administration. For purpose of illustration and not limitation, the various possible forms for the present composition include gels, ointments, creams, lotions, microspheres, liposomes, micelles, foams, lacquers, and non-occlusive transdermal patches, bandages, or dressings, or combinations thereof. Alternatively, the composition may be in the form of a spray, aerosol, solution, emulsion, nanosphere, microcapsule, nanocapsule, as well as other topical or transdermal forms known in the art. In a preferred embodiment, the invention is a gel, a lotion, or a cream. In a most preferred embodiment, the invention is a non-occlusive gel. Gels are semisolid, suspension-type systems. Single-phase gels comprise macromolecules (polymers) distributed substantially uniformly throughout the carrier liquid, which is typically aqueous. However, gels preferably comprise alcohol and, optionally, oil. Preferred polymers, also known as gelling agents, are crosslinked acrylic acid polymers, polyethylene oxides, polyoxyethylene-polyoxypropylene copolymers and polyvinylalcohol; cellulosic polymers (hydroxypropyl cellulose, hydroxyethyl cellulose, hydroxypropyl methylcellulose, hydroxypropyl methylcellulose phthalate, methyl cellulose); gums such as tragacanth and xanthan gum; sodium alginate; and gelatin. In order to prepare a uniform gel, dispersing agents such as alcohol or glycerin can be added, or the gelling agent can be dispersed by trituration, mechanical mixing or stirring, or combinations thereof.
The compositions of the present invention may be manufactured by conventional techniques of drug formulation, particularly topical and transdermal drug formulation, which are within the skill of the art. Such techniques are disclosed in “Encyclopedia of Pharmaceutical Technology, 2nd Ed., edited by J. Swarbrick and J. C. Boylan, Marcel Dekker, Inc., 2002, the content of which is incorporated herein by reference.
EXAMPLESThe following examples are merely illustrative of the present invention and they should not be considered as limiting the scope of the invention in any way, as these examples and other equivalents thereof will become apparent to those skilled in the art in light of the present disclosure and the accompanying claims.
Example 1One embodiment of the formulation according to the invention is a topical gel having Testosterone 1.25% w/w, propylene glycol 5.95% w/w, Ethyl alcohol 45.46% w/w, Distilled water 45.67% w/w, Carbomer (Carbopol 980 NF) 1.21% w/w, Triethanolamine 0.39% w/w, Disodium EDTA 0.06% w/w.
Example 2One embodiment of the formulation according to the invention is a gel composed by testosterone 1.00% w/w, diethylene glycol monoethyl ether 5.00% w/w, propylene glycol 6.00% w/w, ethanol 47.52% w/w, purified water 38.87% w/w, carbomer (CARBOPOL™ 980 NF) 1.20% w/w, triethanolamine 0.35% w/w, and disodium EDTA 0.06% w/w.
Example 3One embodiment of a formulation according to the invention is a topical hydroalcoholic gel formulation with 1% testosterone as the active ingredient. The formulation has been studied in one Phase I/II multiple dose, dose escalating clinical study in women. The study was conducted to determine the effectiveness of the formulation for the treatment of hypoactive sexual desire disorder (“HSDD”), in subjects including surgically menopausal women with low testosterone levels.
This study showed that the testosterone gel dosing between about 0.22 g to about 0.88 g formulation (2.2 to 8.8 mg/day testosterone) daily for 7 days resulted in average total and free testosterone serum concentrations within the normal range or somewhat above the normal range for pre-menopausal women.
Example 4In vitro studies were conducted to determine the permeability profile of testosterone in human surgically excised skin using the testosterone formulation of Table 5 above (containing no lauryl alcohol, “1% T+0% LA”), as compared with other testosterone formulations containing 1% and 2% lauryl alcohol (“1% T+1% or 2% LA”). The results of these studies are presented below in Tables 6, 7 and 8.
In the first study pieces of excised human skin were mounted in Franz Vertical Diffusion Cells (Hansen Research Inc.). Approximately 10 mg of testosterone/cm2 (1% T+0, 1 or 2% LA), were loaded in the loading chamber over the skin, which was maintained at 35° C. Sampling of the receptor solution was performed at selected intervals after loading. The testosterone flux and cumulative amount in the permeability study are shown below in Table 6.
The testosterone flux and cumulative amount for the gel comprising approximately 1.25% testosterone, 5.00% Transcutol, 5.95% propylene glycol, 43.09% ethyl alcohol, 43.07% distilled water, 1.20% Carbopol 980NF, 0.38% triethanolamine, 0.059% EDTA are represented below in Tables 7 and 8.
Another permeation study was conducted using the method described above, except that approximately 50 mg of testosterone/cm2 were loaded in the loading chamber over the skin. Sampling of the receptor solution was performed at selected intervals hours after loading. The testosterone flux and cumulative amount in the permeability study are shown below.
Experience with gel formulations and transdermal patches generally show low rates of mild dermal toxicity with the gels and extensive skin reactions with the patches, probably related to the adhesive used or the occlusive nature of the patch. For instance, with a topical gel formulation of testosterone, a few patients had skin reactions, none of which required treatment or discontinuation of drug. In contrast, transient mild to moderate erythema was observed in the majority of patients treated with a transdermal patch, and some patients had more severe reactions including blistering, necrosis, and ulceration. See for example, Gelas B, Thebault J, Roux I, Herbrecht F, Zartarian M., “Comparative study of the acceptability of a new estradiol Tx 11323 (A) gel and a transdermal matrix system,” Contraception, fertilité, sexualité 1997 June; 25 (6):470-474).
Example 6The objective of this study was to evaluate the safety and pharmacokinetic profiles of multiple doses of a 1% T+0% LA hydroalcoholic gel, in postmenopausal women. During the first 7 days of the study, the subjects received daily topical applications of 0.22 g of a formulation including 1% T+0% LA (2.2 mg/day testosterone). On Days 8-14, the subjects received 0.44 g of a formulation including 1% T+0% LA (4.4 mg/day testosterone), and on Days 15-21, the subjects received 0.88 g of a formulation including 1% T+0% LA (8.8 mg/day testosterone). There was no washout period, prior to each dose escalation. The pharmacokinetic results for total, free and bioavailable testosterone are shown below.
The average baseline total testosterone and free testosterone concentrations were 21.0 ng/dL and 2.6 pg/mL, respectively. After one week of 0.22 g daily doses of 1% T+0% LA, the average total testosterone and free testosterone concentrations were 56.0 ng/dL and 7.0 pg/mL, respectively. One week of daily 0.44 g doses of 1% T+0% LA increased the average total testosterone and free testosterone concentrations to 92.0 ng/dL and 11.1 pg/mL, respectively. Daily doses of 0.88 g 1% T+0% LA for 7 days increased the average testosterone and free testosterone concentrations to 141.5 ng/dL and 16.7 pg/mL in the 7 subjects.
This study demonstrated that 1% T 0% LA has the potential to elevate free testosterone concentrations in women with low endogenous testosterone production. The 0.22 g dose, corresponding to 2.2 mg testosterone, resulted in average free testosterone concentrations towards the upper limit of normal. For the 0.44 g dose, average free testosterone concentrations were 1.6 times the upper limit of normal while average free testosterone concentrations for the 0.88 g dose were approximately 2.4 times the upper limit of normal.
Further, the 1% T+0% LA formulation has been administered in daily testosterone doses of 2.2, 4.4, and 8.8 mg (doses of 0.22 g/day, 0.44 g/day, and 0.88 g/day, each applied for 7 days, respectively) in one Phase I/II study. The formulation was well tolerated in this study. No serious or significant adverse events were reported. No significant changes in clinical laboratory variables, vital signs, ECG parameters or physical findings were detected in any of the treatment groups.
Example 7The primary objectives of this study were to evaluate the safety, tolerability, and pharmacokinetic profile of two different, multiple topical doses of an estradiol gel including in terms of the PK variables AUC and Cmax with and without corrections for endogenous estradiol concentrations in postmenopausal female subjects. Each subject received one of two estradiol treatments for 14 consecutive days; either 1.25 g estradiol gel 0.06% (0.75 mg estradiol/day) or 2.5 g estradiol gel 0.06% (1.5 mg estradiol/day).
Multiple doses of 0.75 mg E2/day maintained average concentrations (=AUCτ/24) of 2.4 ng/dl (24 pg/ml). The double dose of 1.5 mg E2/day resulted in an average concentration of 5.3 ng/dl (53 pg/ml). The values correspond very well to those observed after transdermal patches such as Estraderm®. When using a patch with a nominal delivery rate of 25 μg/day, an average maintenance concentration of 23 pg/ml has been reported. For patches with a delivery rates of 50 μg/day or 100 μg/day, average concentrations of 40 pg/ml and 75 pg/ml have been reported, respectively. Estraderm® has been registered in the European Community and in the United States as being efficacious for postmenopausal disorders including reduction in hot flashes, and for osteoporosis prophylaxis. Therefore, it is predicted that the E2 gel formulation will be safe and effective for treatment of menopausal symptoms including reduction of hot flashes, and for osteoporosis prophylaxis.
Estradiol Concentration Time Data (0-24 hours) Following a Single Dose (Day 1).
Estradiol Trough Concentration Data (Days 1-20).
The median trough values were also examined and these reached a plateau of approximately 5.1 ng/dl E2 at 96 H (Day 5 predose) after application. Thereafter, the trough concentrations were variable and fluctuated between a minimum of 4.2 ng/dl E2 (median at 288 H, Day 13 predose) to a maximum of 5.3 ng/dl at 336 H (Day 15, 0 H). Following the last administration, average E2 concentrations declined to 0.8 ng/dl and were near predose baseline levels (0.5 ng/dl) at 456 H (Day 20, 0 H; 5 days after discontinuation of drug application). Examination of median trough concentrations indicate that steady state E2 concentrations are reached by 4 and 5 days for the E2 gel 1.25 g and 2.5 g doses, respectively.
Estradiol Concentration Time Data (0-24 hours) Following 14 Doses (Day 14).
Estradiol Pharmacokinetic Parameters on Day 1 and Day 14. The pharmacokinetic parameters for E2 following single and multiple applications of Bio-E-Gel at 1.25 g and 2.5 g are presented in Table 10a. A descriptive summary of the pharmacokinetic parameters, uncorrected and baseline-adjusted, are presented in Table 10c and 10d, respectively.
Following a single application of 1.25 g of E2 gel, maximum concentrations (Cmax) on Day 1 were 2.3 ng/dl. On average, the time to maximum concentrations, tmax, was achieved by 17.67H. The exposure to E2, as measured by AUCτ was 27.5 ng/dl*H. Following multiple applications, Cmax concentrations increased to 3.7 ng/dl on Day 14. The tmax estimates were approximately 16 H on Day 14 and were comparable to those observed on Day 1. The exposure to E2 was 57.0 ng/dl*H on Day 14 and was higher than that observed on Day 1, demonstrating the accumulation of E2 in the serum following repeated applications.
Following a single application of 2.5 g of E2 gel, maximum concentrations (Cmax) on Day 1 were 3.7 ng/dl. On average, the time to maximum concentrations, tmax, was achieved by 18 H. The exposure to E2, as measured by AUCτ was 49.7 ng/dl*H. Following multiple application, Cmax concentrations increased to 8.8 ng/dl on Day 14. The tmax estimates were approximately 18 H on Day 14 and were comparable to those observed on Day 1. The exposure to E2 was 128.2 ng/dl*H on Day 14 and was higher than that observed on Day 1, demonstrating the accumulation of E2 in the serum following repeated applications.
The ratio of geometric means of E2 gel 2.5 g/1.25 g was used to assess the dose proportionality of E2 following the two doses of E2 gel. After single dose application, the mean AUC ratio (E2 gel 2.5 g/1.25 g) was 38.4/19.2=2.0 and after multiple doses it was 117.6/51.9=2.3, indicating dose proportionality.
Baseline Adjusted Estradiol Pharmacokinetic Parameters on Day 1 and Day 14. Baseline concentrations of E2 were similar for both groups and were calculated as 0.5 ng/dl and 0.4 ng/dl for the 1.25 g and 2.5 g E2 gel, respectively. In order to correct for endogenous E2 concentrations, the baseline E2 concentration (E2 gel 1.25 g: 0.5 ng/dl and 2.5 g: 0.4 ng/dl) was subtracted from the total concentration measured after application and the AUCτ and Cmax were recalculated based on the baseline-adjusted concentration. The results of the baseline-adjusted pharmacokinetic variables are summarized in Table 10b. The baseline-adjusted Cmax estimates were 1.8 ng/dl and 3.4 ng/dl following single applications of the 1.25 g and 2.5 g E2 gel, respectively. For AUCτ, the baseline-adjusted values were 14.9 ng/dL*H and 41.4 ng/dl*H for the 1.25 g and 2.5 g E2 gel, respectively. Following repeated applications, Cmax estimates increased to 3.1 ng/dl and 8.4 ng/dl and AUCτ estimates increased to 44.2 ng/dl*H and 119.6 ng/dl*H for 1.25 g and 2.5 g E2 gel, respectively. These increases reflect the accumulation of drug in the serum following repeated application of the gel.
The terminal elimination half-life (t1/2) of E2 was calculated from the baseline-adjusted concentrations following the last dose (at 312 H, Day 14 predose) by log-linear regression from the linear portion of the logarithmic transformed concentration-time plot. The individual and mean estimates of half-life following the application of 1.25 g and 2.5 g E2 gel are presented in Table 10d. The median half-life was 22.15 μl (range: 13.11-76.71) for E2 gel 1.25 g and 35.58 μl (range: 26.60-51.59) for 2.5 g. The half-life estimates for both treatment groups were comparable.
Estrone Concentration Time Data (0-24 hours) Following a Single Dose (Day 1).
Estrone Trough Concentration Data (Days 1-20).
The mean E1 trough concentrations following repeated administration of Bio-E-Gel 2.5 g are also presented in
Estrone Concentration Time Data (0-24 hours) Following 14 Doses (Day 14).
Estrone Pharmacokinetic Parameters on Day 1 and Day 14. Following a single application of 1.25 g of E2 gel, maximum concentrations (Cmax) on Day 1 were 3.6 ng/dl. On average, the time to maximum concentrations, tmax, was achieved by 12.67H. The exposure to E1, as measured by AUCτ was 56.2 ng/dl*H. Following multiple applications, Cmax concentrations increased to 6.0 ng/dl on Day 14. The tmax estimates were approximately 11H on Day 14 and were comparable to those observed on Day 1. The exposure to E1 was 111.4 ng/dl*H on Day 14 and was higher than that observed on Day 1, demonstrating the accumulation of E1 in the serum following repeated applications.
Following a single application of 2.5 g of E2 gel, maximum concentrations (Cmax) on Day 1 were 4.1 ng/dl. On average, the time to maximum concentrations, tmax, was achieved by 21H. The exposure to E1, as measured by AUCτ was 62.2 ng/dl*H. Following multiple application, Cmax concentrations increased to 9.2 ng/dl on Day 14. The tmax estimates were approximately 2 H on Day 14 and were lower than those observed on Day 1. The exposure to E1 was 179.7 ng/dl*H on Day 14 and was higher than that observed on Day 1, demonstrating the accumulation of E1 in the serum following repeated applications.
Baseline Adjusted Estrone Pharmacokinetic Parameters on Day 1 and Day 14. Baseline concentrations of E1 were similar for both groups and were calculated as 1.8 ng/dl and 2.0 ng/dl for the 1.25 g and 2.5 g E2 gel, respectively. In order to correct for endogenous E1 concentrations, the baseline E1 concentration (E2 gel 1.25 g: 1.8 ng/dl and E2 gel 2.5 g: 2.0 ng/dl) was subtracted from the total concentration measured after application and the AUCτ and Cmax were recalculated based on the baseline-adjusted concentration. The results of the baseline-adjusted pharmacokinetic variables are summarized in Table 10d. The baseline-adjusted Cmax estimates were 1.8 ng/dl and 2.0 ng/dl following single applications of the 1.25 g and 2.5 g E2 gel respectively. For AUCτ, the baseline-adjusted values were 14.5 ng/dL*H and 17.9 ng/dl*H for the 1.25 g and 2.5 g E2 gel, respectively. Following repeated applications, Cmax estimates increased to 4.2 ng/dl and 7.2 ng/dl and AUCτ estimates increased to 67.1 ng/dl*H and 131.2 ng/dl*H for 1.25 g and 2.5 g E2 gel, respectively. These increases reflect the accumulation of drug in the serum following repeated application of the gel.
Estrone-Sulfate Concentration Time Data (0-24 hours) Following a Single Dose (Day 1).
Estrone-Sulfate Trough Concentration Data (Days 1-20).
On average, E1-S concentrations continued to increase until approximately 312 H (Day 14 predose) although a change in the rate of increase was evident at approximately 240 H (Day 11 predose). Concentrations increased from 34.7 ng/dl at baseline (0 H) to 193.5 ng/dl at 240 H. Thereafter, the trough concentrations were variable and fluctuated between 193.5 ng/dl E1 (at 240 H) to 155.7 ng/dl at 336 H (Day 15, 0 H). Following the last administration, average E1-S concentrations declined to 60.3 ng/dl and were higher than predose baseline levels (34.7 ng/dl) at 456 H (Day 20, 0 H; 5 days after discontinuation of drug application). Examination of mean trough concentrations indicate that steady state E1-sulfate concentrations are reached by 13 and 14 days for the E2 gel 1.25 g and 2.5 g doses, respectively.
Estrone-Sulfate Concentration Time Data (0-24 hours) Following 14 Doses (Day 14).
Estrone-Sulfate Pharmacokinetic Parameters on Day 1 and Day 14. The pharmacokinetic parameters for E1-S following single and multiple applications of E2 gel at 1.25 g and 2.5 g are presented in Table 10e. A descriptive summary of the pharmacokinetic parameters, uncorrected and baseline-adjusted, are presented in Table 10c and 10d, respectively.
Following a single application of 1.25 g of E2 gel, maximum concentrations (Cmax) on Day 1 were 80.2 ng/dl. On average, the time to maximum concentrations, tmax, was achieved by 20.67H. The exposure to E1-S, as measured by AUCτ was 1359.2 ng/dl*H.
Following multiple applications, Cmaxconcentrations increased to 163.5 ng/dl on Day 14. The tmax estimates were approximately 5 H on Day 14 and were lower than those observed on Day 1. The exposure to E1-S was 2834.1 ng/dl*H on Day 14 and was higher than that observed on Day 1, demonstrating the accumulation of E1-S in the serum following repeated applications.
Following a single application of 2.5 g of E2 gel, maximum concentrations (Cmax) on Day 1 were 74.7 ng/dl. On average, the time to maximum concentrations, tmax, was achieved by 20H. The exposure to E1-S, as measured by AUCτ was 1207.4 ng/dl*H. Following multiple applications, Cmax concentrations increased to 253.8 ng/dl on Day 14. The tmax estimates were approximately 3 H on Day 14 and were lower than those observed on Day 1. The exposure to E1-S was 4079.2 ng/dl*H on Day 14 and was higher than that observed on Day 1, demonstrating the accumulation of E1-S in the serum following repeated applications.
Baseline Adjusted Estrone-Sulfate Pharmacokinetic Parameters on Day 1 and Day 14. Baseline concentrations of E1-S were similar for both groups and were measured as 51.3 ng/dl and 36.9 ng/dl for the 1.25 g and 2.5 g E2 gel, respectively. In order to correct for endogenous E1-S concentrations, the baseline E1-S concentration (E2 gel 1.25 g: 51.3 ng/dl and Bio-E-Gel 2.5 g: 36.9 ng/dl) was subtracted from the total concentration measured after application and the AUCτ and Cmax were recalculated based on the baseline-adjusted concentration. The baseline-adjusted Cmaxestimates were 28.8 ng/dl and 37.7 ng/dl following single applications of the 1.25 g and 2.5 g E2 gel, respectively. For AUCτ, the baseline-adjusted values were 165.7 ng/dL*H and 325.5 ng/dl*H for the 1.25 g and 2.5 g E2 gel, respectively. Following repeated applications, Cmax estimates increased to 112.2 ng/dl and 216.9 ng/dl and AUCτ estimates increased to 1602.1 ng/dl*H and 3192.5 ng/dl*H for 1.25 g and 2.5 g E2 gel, respectively. These increases reflect the accumulation of drug in the serum following repeated application of the gel.
Sex Hormone Binding Globulin (SHBG). The SHBG concentrations in the subsequent table were determined in addition to the study protocol, specially in order enable the interpretation of the unexpected accumulation of E2 in Subject 04. The data are tabulated in Table 10 g. Generally the mean SHBG concentrations increased with time, after E2 gel 1.25 g from mean 72.5 nmol/l at 0 H over 80.17 nmol/l to 84.00 nmol/l and after E2 gel 2.5 g from mean 72.5 nmol/l at 0 H over 77.83 nmol/l to 88.83 nmol/l. Subject 04 who received E2 gel 2.5 g showed a similar pattern. The pre-treatment SHBG-concentrations were 58 nmol/l and 53 nmol/l, respectively. 192 H (Day 9 predose) after the first application the SHBG concentration was 58 nmol/l and after 360 H (Day 16, 0 H) it was increase to 71 nmol/l. Subject 04 thus did not appear to differ from the other subjects and the SHBG concentration do not explain the excessive E2 concentrations in this subject.
Pharmacokinetics Conclusions. The pharmacokinetic characteristics were calculated as surrogates for the evaluation of the efficacy. It could be shown that multiple doses of 0.75 mg and 1.5 mg E2 gel resulted in average serum concentrations of about 2.4 ng/dl E2 and 5.3 ng/dl E2, respectively. These values are of a magnitude which are obtained after transdermal patches with a delivery rate of 25 and 50 μg E2 per day and are approved for postmenopausal disorders, including reduction of hot flashes.
Safety Conclusions. Eight adverse events were observed; 7 of them were classified as (possibly) related to the study treatments: 3 and 4 events after the administration of 1.25 g and 2.5 g E2 gel, respectively. Both treatments regimens showed excellent skin tolerability. No severe, serious, or significant adverse events occurred. No drop outs were observed. There were no significant changes in vital signs, ECG, clinical laboratory variables or physical findings. The study medication was well tolerated. There were no relevant differences in safety profile of the two treatments investigated.
Conclusions. The mean and individual serum concentration-time profiles for E2, E1 and E1-S from 1.25 g and 2.5 g E2 gel showed that the two treatments provided drug concentrations that were above the measured baseline levels. The pharmacokinetics of the gel product demonstrate that upon repeated administration a plateau in drug levels is generally reached. In addition, once drug is discontinued, drug levels return to or are near baseline levels within 5 days. The pharmacokinetics of E2, E1 and E1-S suggested dose proportionality for the 1.25 and 2.5 g gel products. Mean parameter estimates in the 2.5 g treatment group were approximately double the estimates in the 1.25 g treatment group on Days 1 and 14.
Estimates of tmax were variable in both treatment groups. At steady-state on Day 14, some estimates of tmax occurred at the beginning of the dosing interval. In these cases, it is possible that serum concentrations continued to rise immediately after a dose due to continued presence of drug from the previously administered dose. The time to maximum concentration following administration of both treatments occurred within 16-20 H after the first application.
The achievement of steady-state was assessed primarily by graphical methods. Mean trough concentrations for E2 in both treatment groups were highly variable but showed no significant increasing trend over the study period. The median trough concentration plots suggested that steady-state was reached for E2 by Day 5 in both treatment groups. Based upon the estimates of t1/2 for E2 obtained in this study (approximately 33 H), steady-state would be achieved after approximately 9 to 10 days of dosing, a finding which is consistent with the results of the graphical analysis. Thus, the pharmacokinetic measurements conducted on Day 14 of treatment should be representative of steady-state. Similar results were observed for E1 and E1-S although concentrations did appear to be more variable and to fluctuate more for these two analytes.
The pharmacokinetic characteristics were calculated as surrogates for the evaluation of the efficacy. It could be shown that multiple doses of 0.75 mg and 1.5 mg E2 gel resulted in average serum concentrations of about 2.4 ng/dl E2 and 5.3 ng/dl E2, respectively. These values are of a magnitude, which are obtained after transdermal patches with a delivery rate of 25 and 50 μg E2 per day and are approved for postmenopausal disorders, including reduction of hot flashes and osteoporosis. Therefore, it is predicted that E2 gel will be proven safe and effective for treatment of menopausal symptoms including reduction of hot flashes and osteoporosis.
Example 8Study of the Safety and Efficacy of Topical E2 Gel Versus Placebo for Treatment of Vasomotor Symptoms in Postmenopausal Females. The objectives of this study were to evaluate the safety and efficacy, and determine the lowest effective dose of E2 gel, administered as a daily regimen, as compared to that of placebo gel in the treatment of vasomotor symptoms in postmenopausal women. Eligible subjects were equally randomized to one of four treatment arms: E2 gel 0.625/day (0.375 mg estradiol), E2 gel 1.25 g/day (0.75 mg estradiol), E2 gel 2.5 g/day (1.5 mg estradiol) or matching placebo gel. Eligible subjects were healthy postmenopausal women, with an estradiol level <20 pg/mL, who exhibited ≧7 moderate to severe hot flushes each day or ≧60 moderate to severe hot flushes total during 7 days of screening.
E2 gel consisted of 0.06% estradiol in a hydroalcoholic gel formulation supplied in single-dose sachets: E2 gel 0.625 g/day (0.375 mg/day E2), E2 gel 1.25 g/day (0.75 mg/day E2), or E2 gel 2.5 g/day (1.5 mg/day E2). Daily topical applications of E2 gel was administered by the subject on the thigh.
Parameters were evaluated including: hot flush occurrence rates and severity. Adverse events, safety laboratory tests, vitals signs, weight, physical examinations, breast examinations, skin irritation were assessed.
Results of the primary analyses of the co-primary efficacy endpoints indicate that the lowest effective dose of E2 gel in the treatment of vasomotor symptoms in postmenopausal women is E2 gel 2.5 g/day (1.5 mg/day E2). In the E2 gel 2.5 g/day treatment group, the difference from placebo of 2.7 in mean change from baseline in the moderate-to-severe hot flush rate at Week 4 was clinically meaningful (i.e., ≧2.0), with a complimentary superiority to placebo in mean change from baseline in daily hot flush mean severity (placebo −0.6; E2 gel 2.5 g/day, −0.9). The analogous differences from placebo in daily hot flush rate for the other E2 gel dose groups were not clinically meaningful (E2 gel 0.625 g/day, 0.7; E2 gel 1.25 g/day, 0.0).
As in the primary efficacy analyses, comparison of treatment groups with respect to the proportion of subjects with a ≧90% reduction in daily moderate-to-severe hot flush rate at Week 4 indicates effectiveness in the E2 gel 2.5 g/day group (55% of subjects), while the other E2 gel dose groups performed similar to placebo (27% to 35%). Furthermore, the median estradiol concentration at Week 4 for the E2 gel 2.5 g/day dose group (33 pg/mL) is in the low end of the expected therapeutic range, with the median concentrations falling below the range for the other E2 gel dose groups (E2 gel 0.625 g/day, 12 pg/mL; E2 gel 1.25 g/day, 23 pg/mL).
Analyses of Efficacy. The primary efficacy evaluation of the clinical effectiveness of E2 gel 0.625 g/day (0.375 mg E2), E2 gel 1.25 g/day (0.75 mg E2), and E2 gel 2.5 g/day (1.5 mg E2) as compared to placebo was determined with respect to change from baseline in daily (moderate-to-severe) hot flush rate at Week 4 and change from baseline in daily hot flush mean severity at Week 4 evaluated in the ITT LOCF Data Set. The baseline measures used in these analyses are based on data obtained during the Screening Period analyses with baseline measures based on data obtained during the Placebo Lead In Period were not included.
The primary analysis of change from baseline in daily hot flush mean severity was based on unadjusted means from the one-way ANOVA model with treatment as the factor. However, in consideration of dissimilarity across treatment groups with respect to mean baseline daily hot flush rates, as well as an apparent treatment-by-site interaction, the primary analysis of change from baseline in daily hot flush rate was based on least-squares means derived from the ANCOVA model with factors for treatment, site, and treatment-by-site interaction, with baseline hot flush rate as the covariate. Only these primary analysis results are discussed.
As secondary efficacy analyses, the analyses of the 2 co-primary endpoints described above were performed on the Evaluable Subject LOCF Data Set. Additional analyses included the proportions of subjects who had a ≧50%, ≧60%, ≧70%, ≧80%, ≧90%, ≧95% or 100% reduction from baseline in daily moderate-to-severe hot flush rate at Week 4, conducted for the ITT LOCF and the Evaluable Subject LOCF Data Sets. For the ITT Data Set, the results of these proportion analyses are presented in a text table.
Descriptive analyses of the 2 co-primary endpoints were performed for the ITT Observed-Case Data Set and the Evaluable Subject Observed-Case Data Set at Week 1, Week 2, Week 3, and Week 4. Since only 4 subjects discontinued treatment prematurely, the results of the observed-case analyses on these data sets are nearly identical to those from the LOCF analyses and are therefore not discussed explicitly in this report.
Mean Change from Baseline in Daily Moderate-to-Severe Hot Flush Rates. Intent-to-Treat Data Set—LOCF Analyses. In the LOCF analyses of the ITT Data Set, mean reductions from baseline in daily moderate-to-severe hot flush rates were observed for all four treatment groups, with a more pronounced reduction observed in the E2 gel 2.5 g/day dose group (see Table 11a and
A clinically significant difference (i.e., ≧2.0) was observed between the E2 gel 2.5 g/day group and placebo in the mean reduction of daily hot flush rate at Week 4 (difference between groups=−2.7), while the two lower doses of E2 gel did not show a clinically meaningful difference from placebo. Therefore, the two lower E2 gel doses are non-effective and the E2 gel 2.5 g/day dose is demonstrated to be the lowest effective dose for the treatment of moderate-to-severe hot flushes.
Evaluable Subject Dataset—LOCF Analyses. In the LOCF analyses of the Evaluable Subject Data Set, mean reductions from baseline in daily moderate-to-severe hot flush rates were observed for all 4 treatment groups, with a more pronounced reduction observed in the E2 gel 2.5 g/day dose group (see Table 11b and
Proportion of Subjects with ≧90% or 100% Percent Reductions in Daily Moderate-to-Severe Hot Flush Rates at Week 4. Intent-to-Treat Data Set—LOCF Analyses. In the LOCF analyses of the ITT Data Set, the majority (55%, 21/38) of subjects in the E2 gel 2.5 g/day dose group experienced a ≧90% reduction in daily moderate-to-severe hot flush rate at Week 4, compared to approximately a third of subjects in placebo and the two lower E2 gel dose groups (see Table 11c). Twenty-four percent (24%) of subjects in the E2 gel 2.5 g/day dose group had a 100% reduction (i.e., no moderate-to-severe hot flushes) at Week 4.
Mean Change from Baseline Severity of Hot Flushes. Intent-to-Treat Data Set—LOCF Analyses. In the LOCF analyses of the ITT Data Set, mean reductions from baseline daily hot flush mean severity were observed for all four treatment groups, with a more pronounced reduction observed in the E2 gel 2.5 g/day dose group, and to a lesser degree, in the E2 gel 1.25 g/day dose group (see Table 11d and
Drug Dose, Drug Concentration, and Relationships to Response. Estradiol, Estrone, and Estrone Sulfate. Trough serum samples were obtained prior to dosing on Day 1 and upon study completion for determination of estradiol, estrone, and estrone sulfate concentrations. For summarization, all assay results below the detection limit of 5 pg/mL were set equal to the limit (i.e., assigned a value of 5 pg/mL). Trough concentrations of estradiol, estrone, and estrone sulfate at Day 1 and Week 4 were highly variable within treatment groups (see Table 11e). In consideration of the variability and the moderate sample sizes, median values will be discussed.
Across all treatment groups, median values at Day 1 for estradiol (5 pg/mL), estrone (18.5 to 22.0 pg/mL), and the estradiol-to-estrone ratio (0.29 to 0.42) were consistent with a postmenopausal profile (see Table 11e). However, note that some subjects who met the inclusion criterion of <20 pg/mL estradiol at screening failed to meet this criterion at Day 1. Apart from variability inherent to the assay, speculative reasons for this are instability of hormone levels for subjects with menopause onset within the prior year, hysterectomy without oopherectomy in subjects <50 years of age, or possible unreported noncompliance regarding use of an estrogen product during the Screening Period.
After therapy with E2 gel, median estradiol, estrone, and estrone sulfate concentrations at Week 4 showed separation between treatment groups in accord with E2 gel dose administration (see Table 11e). The median estradiol values at Week 4 were 12 pg/mL, 23 pg/mL, and 33 pg/mL, respectively, for the E2 gel 0.625 g/day, 1.25 g/day, and 2.5 g/day dose groups.
Safety Conclusions. Daily application of 0.625-2.5 g E2 gel (0.375-1.5 mg estradiol) for approximately 4 weeks was safe and well-tolerated in this population of postmenopausal females. The overall incidence of treatment-emergent adverse events among the E2 gel groups was not increased with dose level (approximately 50% in each dose group), and compared well to the incidence in the placebo group (40%). Adverse events associated with reproductive system and breast disorders were reported more frequently in the E2 gel groups (10%, 18%, and 13% in the 0.625 g/day, 1.25 g/day, and 2.5 g/day E2 gel groups, respectively) versus placebo (5%), as would be expected in this class of drugs. These events reported in 2 or more E2 gel subjects included: breast tenderness, metrorrhagia (vaginal spotting), nipple pain, uterine spasm, and vaginal discharge. No relationship was apparent between the incidence of these events and E2 gel dose or estradiol level. No subjects discontinued the study due to these events.
Breast examination indicated no effect of E2 gel at final evaluation for all but one subject; the change observed for this subject (E2 gel 2.5 g/day) corresponded to one of the reported adverse events of mild breast tenderness, which resolved one week after final study drug administration.
No deaths or serious adverse events occurred during the study. Two (2) subjects (both E2 gel 1.25 g/day) discontinued double-blind treatment due to an adverse event, only one of which (dizziness) was considered possibly related; both subjects recovered.
No clinically meaningful effects of E2 gel on clinical laboratory results were observed in analyses of mean change from baseline to Week 4 evaluations. Comparisons of proportions of subjects with shifts from normal baselines to abnormal levels at Week 4 indicated a higher incidence of shifts to above normal cholesterol levels in E2 gel groups, and an apparent E2 gel dose-related increased incidence of shifts to above normal BUN levels; however, only about 10 subjects per group were included in the cholesterol comparison (since most subjects had above normal baseline cholesterol levels), and the BUN shifts were not associated with corresponding shifts in other renal function indicators or clinical manifestations of renal insufficiency.
No clinically important effects of E2 gel were observed for vital signs, body weight, physical examinations, or skin irritation assessment.
Conclusion. Transdermal ET delivers estradiol directly into the systemic circulation via the skin, thus avoiding the first-pass hepatic metabolism that occurs with oral ET and avoiding the effects on the hepatobiliary system seen with oral ET. No statistically significant or clinically meaningful changes noted in the mean change from baseline to Week 4 evaluation were observed for any liver function parameters. One subject in the E2 gel 0.625 g/day dose group experienced an increased AST that the investigator felt was clinically significant; also this subject had an elevated ALT (44 u/L) at baseline that increased to 70 u/L at final evaluation. No subjects were observed to have clinically significant increases in liver function tests in the E2 gel 1.25 g/day or E2 gel 2.5 g/day dose groups.
Adverse events associated with the topical application of the study gel were minimal and were more frequently reported in the E2 gel 1.25 g/day dose group. Dry skin at the application site was the most frequently reported event associated with the application of study drug, occurring in two subjects. These events were considered mild, with the onset greater than 2 weeks on study drug, and the events lasted no longer than 7 days. Other skin related events reported included burning or itching at the application site, occurring in one subject for each event. No treatment-emergent erythema at application site occurred.
Oral ET has been shown to produce an increase in the biliary cholesterol saturation index, and is associated with an increased risk of gallstones disease; however, this effect does not appear to be evident in transdermal ET. No subjects in the E2 gel dose groups were noted to have clinically significant changes in bilirubin levels, and no adverse events related to increased cholesterol, bilirubinemia, or gallstones were reported.
While it was initially thought that the use of transdermal ET would avoid the increases in serum lipids and lipoproteins seen with oral ET, studies have shown that changes in serum lipids and lipoproteins do occur, but with onset and progression that is slower than with oral ET. In this 4 week study, clinically meaningful mean changes were not observed in these parameters, though overall changes would not be expected in just a 4-week duration of treatment. One subject in the E2 gel 2.5 g/day dose group had a clinically significant change from baseline in triglycerides; however, the subject's final laboratory blood draw was non-fasting. Incidentally, this subject's baseline cholesterol was 287 mg/dL and LDL was 172 mg/dL.
The results of this study demonstrate that E2 gel administered daily in doses of 0.625-2.5 g/day for 4 weeks is safe and well-tolerated.
In accordance with the invention, the formulation may be provided in a kit including the formulations described above, as well as instructions for use of the same. The kit generally includes a container that retains the formulation and has a dispenser for releasing or applying a predetermined dosage or predetermined volume of the formulation upon demand. The dispenser can also automatically release the predetermined dosage or volume of the composition upon activation by the user.
The kit of the present may include the formulations in a pouch, tube, bottle, or any other appropriate container. The kit may include a single doses of the formulation packaged in individual sachets, such that each day a user opens and applies the amount of the composition included in the sachet as the dosage of the active ingredient. The kit may also include multiple doses of the composition packaged in a container. During use, the subject may be instructed to dispense a given amount of the composition from the container for application to the skin (such as a “dime-sized amount”, or the like). Storage of the compositions according to this invention may be in aluminum tubes at about 25° C. and 60% relative humidity as well as 40° C. and 75% relative humidity at least for about 6 weeks.
The container may include a metered dispenser, such that a known volume or dosage of the formulation is dispensed by the user at each activation of the dispenser. In one example, the formulation may be supplied in a metered dose pump bottle. The formulation provided may be in a concentration such that a certain weight or volume (such as 0.87 g) may be dispensed from each depression on the pump, and multiple activations of the pump, such as three times, may dispense the desired dosage of the formulation for the application by the subject. In one example, the kit includes a gel formulation included within a container such as an Orion metered dose pump bottle. Although containers other than pump bottle type container may be used, e.g., stick, or roll-on containers, and the like.
Example 9Pilot pharmacokinetic study of an oxybutynin gel formulation of the present invention in healthy volunteers
In vivo study was conducted by a qualified investigator to determine the pharmacokinetics of oxybutynin in healthy human volunteers. The study was a single-center, multiple-dose, open-label study during which the following oxybutynin gel formulation was tested. This gel included oxybutynin free base 3% w/w, ethanol 96% v/w ˜55% w/w, diethylene glycol monoethyl ether 2.5 w/w, propylene glycol 20% w/w, hydroxypropylcellulose (KLUCEL™ HF Pharm) 1.5 w/w, butylhydroxytoluene (BHT) 0.05% w/w, hydrochloric acid HCl q. ad. for pH 7 to 8, and purified water q. ad. for 100% w/w, and was prepared by dissolving the oxybutynin free base in the ethanol/propylene glycol/diethylene glycol monoethyl ether mixture. Purified water was then added and pH adjusted to the target with hydrochloric acid solution. Hydroxypropylcellulose was then thoroughly dispersed in the hydro-alcoholic solution under mechanical stirring at room temperature at a suitable speed ensuring good homogenization of the formulation while avoiding lumps formation and air entrapment until complete swelling. The BHT was added to the ethanol/propylene glycol/diethylene glycol monoethyl ether mixture.
This study was planned and performed in accordance with the Declaration of Helsinki in its version of Somerset West, 1996, and in accordance with the EU Clinical Trial Directive 2001/20/EC and relevant guidances (“Note for Guidance on Good Clinical Practice”, CPMP/ICH/135/95 of Jan. 17, 1997; “Note for Guidance on the Investigation of Bioavailability and Bioequivalence”, CPMP/EWP/QWP/1401/98; “Note for Guidance on modified release oral and transdermal dosage forms: Section II”, CPMP/EWP/280/96). Treatment consisted in multiple doses of 2.8 g of gel per day (corresponding to 84 mg oxybutynin per day) administered each morning for 7 consecutive days. The gel was distributed over a skin area of 700 cm2 on the abdomen. 58 non-smoking males and females (including 25-40 women), aged 18 to 55, white, physically and mentally healthy as confirmed by an interview, medical history, clinical examination and having given written informed consent, enrolled in this study. Summary data on study population are presented in Table 12 herein. 54 subjects completed the study. Blood sampling was performed on Day 1 at initiation of the study (H0), and then on Day 7 (H0+144; H0+146; H0+148; H0+152; H0+156), Day 8 (H0+160; H0+164; H0+168), Day 9 (H0+192), Day 10 (H0+216), Day 11 (H0+240) and Day 12 (H0+264). Blood samples were then processed and analyzed by LC-MS-MS method (LLOQ set to 50 ng/ml). Criteria considered for evaluation were Pharmacokinetics (oxybutynin and N-desethyloxybutynin), area under the concentration-time curve (AUCτ), highest concentration determined in the measuring interval (Cmax), and adverse events and vital signs. Summary results of this study are presented in Table 13 and in Table 14 herein.
Plasmatic oxybutynin concentration reached a steady state after 6 repeated doses. The average plasmatic concentration of oxybutynin was 5.99 ng/ml. Cmax was 8.61 ng/ml (geometric mean). Tmax, the time at which the concentration of oxybutynin (Cmax) peaks, occurred about 4 hours (median) after application. The terminal half-life T1.2 was 28.16 hours (geometric mean). See
Plasmatic N-desethyloxybutynin concentration reached also steady state after 6 repeated doses. The average plasmatic concentration of oxybutynin was 5.74 ng/ml. Cmax was 7.69 ng/ml (geometric mean). Tmax, the time at which the concentration of oxybutynin (Cmax) peaks, occurred about 8 hours (median) after application. The terminal half-life T1/2 was 30.11 hours (geometric mean). See
The majority of the reported adverse events (AEs) was classified as related to the study medication itself. The most often observed AE was dry mouth (13% of subjects), reported as a common side-effect of oxybutynin. The other common side-effects were reported infrequently (5% of subjects or less). The observed skin-tolerability of the treatment was good, with only eight subjects reporting mild skin reactions. No significant changes in vital signs, electrocardiogram parameters, physical findings or in clinical laboratory variables were detected. The results are shown in Table 15 herein.
Additional examples of oxybutynin formulations have been presented in U.S. application Ser. No. 12/614,216 and are expressly adopted herein by reference thereto.
Additional examples of formulations of other active agents, such as selegilline, fentanyl, and buspirone, can be found in U.S. Pat. No. 7,335,379.
While the invention has been described and pointed out in detail with reference to operative embodiments thereof, it will be understood by those skilled in the art that various changes, modifications, substitutions, and omissions can be made without departing from the spirit of the invention. It is intended therefore, that the invention embrace those equivalents within the scope of the claims that follow.
Claims
1. A delivery vehicle for a composition of an active agent that is to be administered transdermally or transmucosally to a subject, which comprises a C2 to C4 alkanol, a polyalcohol, a monoalkyl ether of diethylene glycol, and water, present in relative amounts sufficient to provide permeation enhancement of the active agent through mammalian dermal or mucosal surfaces; wherein the delivery system is substantially free of long-chain fatty alcohols, long-chain fatty acids, and long-chain fatty esters in order to avoid undesirable odor and irritation effects caused by such compounds during use of the composition.
2. The delivery vehicle of claim 1, wherein the alkanol is selected from the group consisting of ethanol, isopropanol, n-propanol, and mixtures thereof; wherein the polyalcohol is selected from the group consisting of propylene glycol and dipropylene glycol and mixtures thereof; and wherein the monoalkyl ether of diethylene glycol is selected from the group consisting of monomethyl ether of diethylene glycol, monoethyl ether of diethylene glycol, and mixtures thereof.
3. The delivery vehicle of claim 1, wherein the alkanol is present in an amount between about 5 to 80% by weight, the polyalcohol is present in an amount between about 1% to 30% by weight, and the monoalkyl ether of diethylene glycol is present in an amount between about 0.2 to 30% by weight so that the delivery vehicle facilitates absorption of the active agent by the dermal or mucosal surfaces so that transfer or removal of the formulation from such surfaces is minimized.
4. The delivery vehicle of claim 3, wherein the alkanol is in combination with water to form a hydroalcoholic mixture that is present in an amount of between about 40 to about 98% by weight, with the alkanol present in an amount of between about 5% to 80% by weight of the mixture, and the water present in an amount of between about 20% to 95% by weight of the mixture.
5. The delivery vehicle of claim 1, wherein the alkanol is present in an amount between about 45 and 75% by weight; the polyalcohol is present in an amount between about 1 to 30% by weight; and the monoethyl ether of diethylene glycol is present in an amount between about 1 to 15% by weight.
6. The delivery vehicle according claim 1, wherein the alkanol is ethanol, isopropanol, or a mixture thereof present in an amount between about 45 and 60% by weight; the polyalcohol is propylene glycol present in an amount between about 1 to 20% by weight; and the monoethyl ether of diethylene glycol is present in an amount between about 1 to 10% by weight and further wherein the polyalcohol and permeation enhancer are present in a weight ratio of between 1:1 to 3:1.
7. The delivery system according to claim 6 consisting essentially of the recited ingredients and amounts.
8. A non-occlusive formulation comprising the delivery vehicle according claim 1 and an active agent or a pharmaceutically acceptable salt thereof present in an amount of between about 1 to 20% by weight of the formulation; wherein the formulation is substantially free of long-chain fatty alcohols, long-chain fatty acids, and long-chain fatty esters in order to avoid undesirable odor and irritation effects caused by such compounds during use.
9. The formulation of claim 8, wherein the active agent is a hormone,
10. The formulation of claim 8 wherein the active agent is selected from the group consisting of an androgen, estrogen, progestin, or a combination thereof; wherein the androgen is selected from the group consisting of testosterone, 17-β-hydroxyandrostenone, testosterone esters, methyl testosterone, testolactone, oxymetholone, fluoxymesterone, androsterone, androsterone acetate, androsterone propionate, androsterone benzoate, androstenediol, androstenediol-3-acetate, androstenediol-17-acetate, androstenediol-3,17-diacetate, androstenediol-17-benzoate, androstenediol-3-acetate-17-benzoate, androstenedione, sodium dehydroepiandrosterone sulfate, 4-dihydrotestosterone, 5 adihydrotestosterone, dromostanolone, dromostanolone propionate, ethylestrenol, nandrolone phenpropionate, nandrolone decanoate, nandrolone furylpropionate, nandrolone cyclohexanepropionate, nandrolone benzoate, nandrolone cyclohexanecarboxylate, oxandrolone, and stanozolol or any combination thereof; the estrogen is selected from the group consisting of 17 beta-estradiol, estradiol, estradiol benzoate, estradiol 17 beta-cypionate, estriol, estrone, ethynil estradiol, mestranol, moxestrol, mytatrienediol, polyestradiol phosphate, quinestradiol, and quinestrol or any combination thereof; and the progestin is selected from the group consisting of allylestrenol, anagestone, chlormadinone acetate, delmadinone acetate, demegestone, desogestrel, dimethisterone, dydrogesterone, ethynilestrenol, ethisterone, ethynodiol, ethynodiol diacetate, fluorogestone acetate, gestodene, gestonorone caproate, haloprogesterone, 17-hydroxy-16-methylene-progesterone, 17 alpha-hydroxyprogesterone, 17 alpha-hydroxygesterone caproate, lynestrenol, medrogestone, medroxyprogesterone, megestrol acetate, melengestrol, 16-methylene-17-alpha-acetoxy-19-nor-pregn-4-ene,3,20-dione, norethindrone, norethindrone acetate, norethynodrel, norgesterone, norgestimate, norgestrel, norgestrienone, 19-norprogesterone, norvinisterone, pentagestrone, progesterone, natural progesterone, promegestone, quingestrone, and trengestone or any combination thereof; provided that the combination of estrogen and progestin is not present.
10. The formulation of claim 8, wherein the pharmaceutically acceptable salt of the active agent is selected from the group consisting of acetate, bitartrate, citrate, edetate, edisylate, estolate, esylate, fumarate, gluceptate, gluconate, glutamate, hydrobromide, hydrochloride, lactate, malate, maleate, mandelate, mesylate, methylnitrate, mucate, napsylate, nitrate, pamoate, pantothenate, phosphate, salicylate, stearate, succinate, sulfate, tannate and tartrate.
11. The formulation of claim 8, further comprising at least one excipient selected from the group consisting of gelling agents, solvents, cosolvents, antimicrobials, preservatives, antioxidants, buffers, humectants, sequestering agents, moisturizers, emollients, film-forming agents, or permeation enhancers.
12. The formulation of claim 8, in the form of a topical gel, lotion, foam, cream, spray, aerosol, ointment, emulsion, microemulsion, nanoemulsion, suspension, liposomal system, lacquer, or non-occlusive dressing.
13. The formulation of claim 8, wherein the alkanol is ethanol or isopropanol that is present in an amount between about 20 to 65% of the formulation; the polyalcohol is propylene glycol that is present in an amount between about 1% to 15% of the formulation; the permeation enhancer is diethylene glycol monoethyl ether that is present in an amount between about 1% to 15% of the formulation, and further wherein the formulation comprises a gelling agent present in an amount of between 0.05% to about 4% of the formulation, a neutralizing agent present in an amount between about 0.05% and 1% of the formulation, and water present in an amount between about 20% to 65% of the formulation, and wherein the active agent is either estradiol present in an amount between about 0.01% to about 2% of the formulation or testosterone in an amount of about 0.01 to about 1% by weight.
14. A method for administering an active agent to a mammal in need thereof which comprises topically or transdermally administering to the skin or the mucosa of the mammal a formulation according to claim 8.
15. The method of claim 14, wherein the active agent is present in an amount of about 0.01 to about 5% of the composition and between about 40 and about 250 mg of the composition is administered daily upon the abdomen, shoulder, arm, or thigh of the mammal.
Type: Application
Filed: Mar 9, 2011
Publication Date: Aug 11, 2011
Applicant:
Inventors: Dario Norberto R. Carrara (Oberwil), Arnaud Grenier (Steinbrunn le haut)
Application Number: 13/044,447
International Classification: A61K 9/127 (20060101); A61K 47/10 (20060101); A61K 31/568 (20060101); A61K 31/565 (20060101); A61P 5/26 (20060101); A61P 5/30 (20060101); A61P 15/00 (20060101); A61P 19/10 (20060101);
