IMPLANTABLE DRUG DELIVERY SYSTEM
An implantable medicament delivery device includes a core body which further includes a single basin or multiple smaller basins for containing a drug or a medicament. Each basin is covered by a screen. The implantable drug delivery device is placed within the body of an animal, and the drug is allowed to diffuse through the holes in the screen to provide treatment of a disease or condition.
This application is a continuation of patent application Ser. No. 10/385,791, filed Mar. 11, 2003, which claims priority from U.S. Provisional Patent Application, Ser. No. 60/363,150 filed Mar. 11, 2002.
FIELDThe present invention pertains to a drug delivery system; more particularly, the present invention pertains to an implantable small drug delivery device for use with human beings or other animals.
BACKGROUNDThere are many conditions or diseases which occur within the body of a human being or an animal which respond effectively to treatment by the use of one or more medicaments. For many such conditions and diseases the medicament is taken orally. Once swallowed, the medicament eventually migrates to the location of the condition or disease by passing through the gastrointestinal system. In still other instances, medicament is delivered to the location of the condition or disease through the bloodstream. Specifically, the medicament is injected by a syringe into a muscle or soft tissue and then carried by the flow of blood. In still other situations, generally in a health care facility, an IV drip may be used to place the medicament directly into a blood vessel. In yet other situations, some type of surgical intervention is used to physically place a particular medicament within the body at or near the location of a condition or disease.
It has been found that by use of the techniques developed for the creation of integrated circuits, small drug delivery devices can be manufactured which may be used to both contain and then deliver medicament to the site of a condition or disease within the human body. Examples of such small drug implantation devices are disclosed in the following U.S. patents: U.S. Pat. No. 5,770,076; U.S. Pat. No. 5,797,898; U.S. Pat. No. 5,985,328; U.S. Pat. No. 6,123,861, and U.S. Pat. No. 6,331,313. Many of these small drug implantation devices are highly complex and, accordingly, both difficult and expensive to manufacture. Thus, there remains a need in the art for a simple, low cost, easy-to-manufacture implantable small drug delivery device that can be adapted for implantation within the body of a human being or other animal to deliver medicament to a wide variety of locations.
SUMMARYThe simple, low cost, easy-to-manufacture implantable drug delivery system of the present invention enables the implantation of a mechanism within the body to deliver medicament to a wide variety of locations. The disclosed system includes at least one basin, well, or open space. The basin, well, or open space is enframed, enclosed, encased, or formed in a core body. The basin, well, or open space within the core body or basin encasement portion is of sufficient size to contain the desired amount of a medicament needed for prolonged internal treatment of a chronic condition or disease. Typical of such chronic conditions or diseases are those that are known to occur within the eye.
Covering the basin, well, or open space, which is surrounded by the core body, at either the top, or the bottom, or both, is a screen. The screen is used to control the release or movement of a drug or a medicament from a tablet, a powder, or a slurry placed in the basin, well, or open space into the body of a human or an animal. The number, size, location, and arrangement of the holes in the screen or screens is a function of the solubility of the medicament contained in the basin, well, or open space, the dissolution rate of the medicament, the concentration of the medicament, and the form of the medicament—be it a tablet, a powder, a slurry, or a combination thereof.
Once one or more medicaments have been placed into the basin, well, or opening, and the basin, well, or opening is covered with a screen, the entire combination of the drug or medicament, the core body in which the basin is formed, and the screen is implanted within the body. For example, for conditions or diseases occurring within the eye, one technique is to insert the disclosed drug delivery system into the eye through the sclera portion. Once the disclosed drug device has been properly positioned at its desired location, it may be affixed in place using a variety of methods, to include passing sutures through a hole formed in the core body.
Dispersion of the medicament out of the basin, well, or open space occurs when fluid from within the body moves through the perforations in the screen into the basin. This flow of fluid through the screen initiates the dissolution of the medicament within the basin. The dissolved medicament will then slowly diffuse outwardly through the holes in the screen to provide continuing treatment of the condition or disease as long as a quantity of medicament remains within the basin of the disclosed drug delivery device.
A better understanding of the implantable drug delivery system of the present invention may be had by reference to the drawing figures, wherein:
In the following description of the preferred and alternate embodiments, reference numbers are used to facilitate the description of the disclosed invention. Throughout this description, the same numbers in the units and tens places refer to the same portion of each embodiment. The numbers in the hundreds and thousands places are used to designate an alternate embodiment.
As may be seen in
While the preferred embodiment of the present invention is described herein according to its use for treatment of inner eye diseases, it will be understood by those of ordinary skill in the art that the present invention may be used at any location in the body of an animal suitable for the treatment of a disease or condition with medicament contained in a small drug delivery device.
In addition to treatment of the diseases of the eye, a drug delivery device according to the present invention could be positioned adjacent to the prostate gland in men for the treatment of prostate cancer or benign prostate hyperplasia. By using the disclosed device, the negative side effects normally associated with the treatment of prostate cancer, such as hot flashes, vocal changes, or breast enlargement could be significantly reduced or even eliminated. In addition, those of ordinary skill in the art will understand that the amount of a drug or medicament needed for treatment of a disease or condition could be significantly reduced, thus reducing patient cost. Patient compliance with a treatment regimen would improve as the need for frequent drug administration would effectively be eliminated. Pharmacist workload and exposure to hazardous or toxic pharmaceuticals would be reduced. The opportunity for drug-drug or drug-food interaction would be effectively avoided. And the opportunity to provide drug combination therapy would be increased.
Similar advantages could also be obtained if the disclosed device instead included a contraceptive implanted within a female. Still other potential applications include the treatment of vaginal fungal infections with an anti-fungal medicament.
Victims of Parkinson's disease would also be candidates for implantation of the disclosed drug delivery device within the brain to slowly release medicament for reduction of tremors. Patients with ulcerative colitis or a variety of different gastroenterological diseases may also be able to obtain relief by implantation of the disclosed device in their GI tract.
As may be seen in
A still better understanding of the construction of the core body 12 may be had by reference to
The basin 14 may be located at the center of the core body 12 as shown in
To minimize the formation of small bubbles within the basin 14, it is preferable that the size and shape of the basin 14 and the size and shape of the medicament placed in the basin 14 should be substantially the same to minimize the amount of free air.
As shown in
As may be seen in
A suitable thickness for each screen will be from about 0.05 mm to 0.5 mm, and a suitable thickness of the core body 12 will be from about 0.5 mm to about 3.0 mm, preferably about 1.0 mm to about 2.0 mm, depending on the amount of medicament that is intended to be administered at the target implantation site.
When either metallic or non-metallic materials are used to fabricate the disclosed drug delivery device, the screen 24 or screens 24, 26 may be affixed to the core body 12 using a variety of different adhesives, to include silicon rubber, cyano acrylates, or commonly available bio-compatible room temperature adhesives, thermal adhesives, epoxies, or ultraviolet light cured adhesives. In the preferred embodiment, the screen 24 or screens 24, 26, like the core body 12, are also formed to be substantially planar.
A variety of different materials may be used to fabricate the core body 12 and the screens 24, 26. Such materials may be selected from a variety of different bio-compatible materials to include silicon, glass, ruby, sapphire, diamond, or ceramic. If desired, a bio-compatible metal may be used to form the core body 12 and the screens 24, 26. Such bio-compatible metals include gold, silver, platinum, stainless steel, tungsten, and titanium. When a bio-compatible metal is used, the screen 24 or screens 24, 26 may be welded to the core body 12 using a variety of different techniques, to include laser welding, thermo-electro bonding, as previously indicated, or the glues and adhesives described above.
Those of ordinary skill in the art will understand that the effectiveness of the disclosed drug delivery platform is determined by the delivery of the appropriate number of molecules of medicament during a predetermined period of time. Accordingly, the sum total of the area of the holes 28 in the screen or screens must enable the desired delivery rate of medicament from the basin 14. Generally, this is referred to as hole density. For the purposes of this disclosure, hole density is the total area of the holes divided by the total surface area of the device, even that area not covered by a screen.
The number of holes, their size, their location, and their general appearance on the surface of a screen forms a hole pattern. This hole pattern will be adjusted to assure that required amount of medicament is delivered at the needed flow rate. When multiple basins are formed in the core body, multiple hole patterns in the screens may be used to control the flow of medicament. For example, a hole pattern having holes concentrated at one end of a basin will initially cause a fast flow of medicament. But, as the medicament is used up, the medicament will have a longer path to travel before exiting the basin 14; accordingly, the release rate of medicament out of the drug delivery basin 14 will drop off over time.
In an alternate embodiment 110 shown in
While the preferred embodiment shows a modified racetrack perimeter 36 with the basin 14 closer to the distal end 15 and a suture hole 30 placed at the proximal end 13, it will be understood by those of ordinary skill in the art that numerous other designs of the implantable drug delivery platform are possible without departing from the scope of the present invention. For example, the drug delivery platform may be formed with multiple suture holes 30 or with straight sides such as the triangle shape 310 as shown in
Because of the adaptability of the disclosed invention to being configured in a variety of different shapes, particularly if the core body and screen(s) are formed of a bio-compatible metal, the disclosed device may be formed as a ring or in a cylinder 380, as shown in
If desired, different types of medicaments may be placed in different core bodies having different shapes or different colors. The use of different medicaments in different shaped or colored core bodies will reduce confusion of medications by enabling surgeons to distinguish between medicaments by the shape or color of the device in which the medicament is contained.
In certain situations it may be necessary to orient the drug delivery device in a particular position with regard to the condition or disease being treated. In such situation, the drug delivery device 410 may be attached to a support piece 432 as shown in
In still another embodiment of the drug delivery platform 510 as shown in
In yet another alternate embodiment 610, as shown in
While sufficient medicament can be placed within the basin of the core body to treat the condition or disease for a minimal or prolonged period of time, it may be necessary to actually replace the medicament if the condition or disease is particularly persistent. While the entire device may be replaced, it has been found that when the device is used inside a patient for a prolonged period of time, such as a year or more, the basin 714 within the core body 712 may be refilled by the use of a passageway 738 running from the perimeter edge 736 of the core body 712 into the basin 714 as shown in
In still another embodiment 810, the end of the passageway 838 may be attached to a flange 840. The flange 840 facilitates location of the opening for the refilling of the basin 814 with a medicament by the use of a syringe (not shown). In addition, the use of a flange 840 may prevent or reduce contamination. The flange 840 may be located on the side of the core body 812 or a short distance away and connected by a small tube 842. The passage way 838 may be formed as a tortuous path as shown in
In complex situations, it may be necessary to place multiple medicaments near the site of the condition or disease. In such cases multiple basins may be formed within the core body 943, 945. As shown in
Still other embodiments of the disclosed drug delivery platform appear in
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Devices similar to those depicted in
In an in vitro study, betaxolol HCl, a relatively high water soluble substance, was tableted with 10% microcrystalline cellulose and 0.40% magnesium stearate with a total weight of 22 mg. The betaxolol HCl tablet was inserted into the basin of a drug delivery devices similar to the embodiment depicted in
In a second in vitro study, another second drug formulation using a substance with a relatively low water solubility, nepafenac in tablet form, was also studied in a device similar to the embodiment depicted in
Once a medical condition or disease within the body is identified and located, a physician will determine whether or not such condition or medication may be treated with a medicament placed in close proximity to site of the condition or disease. If the decision is made to treat the condition or disease with a medicament placed close to the condition or disease, it then becomes necessary to actually place the medicament near the condition or disease. In other applications, it may be necessary to treat a condition or disease from a short distance. Such short distance treatment may require sustained levels of medicament flow from the drug delivery device.
In the embodiment 10 shown in
To prevent coating of the implanted devices with cells which can block the movement of medicament from the basin through the holes in the screen, an anti-proliferative coating may be used on both the screen and core body. Similarly, materials such as silicon may form chips so as to prevent chipping the screen, and the core body may be coated with a substance to prevent chipping.
As previously mentioned, while the preferred embodiment is shown for the purpose of inserting medicament to treat a condition or disease within the inner eye, those of ordinary skill in the art will understand that the disclosed implantable drug delivery platform 10 may be used at any location within the body of an animal where a condition or disease is best treated with an implanted medicament.
The present invention, having now been disclosed according to its preferred and alternate embodiments, will now be understood by those of ordinary skill in the art. Those of ordinary skill in the art will understand that numerous other embodiments of the present invention may also be embodied by the foregoing disclosure. Such other embodiments shall be included within the scope and meaning of the appended claims.
Claims
1. A method of making implantable drug delivery platform comprising the steps of:
- a) forming a basin containment portion around a basin, said basin being constructed and arranged to contain the drug;
- b) affixing a first screen to said basin containment portion to cover said basin.
2. The method as defined in claim 1 further including the step of placing a second screen on the opposite side of said basin.
3. The method as defined in claim 2 wherein said second screen is affixed to said basin containment portion.
4. The method as defined in claim 1 wherein said basin containment portion is substantially planar.
5. The method as defined in claim 1 wherein said first screen is formed to be substantially planar.
6. The method as defined in claim 2 wherein said second screen is formed to be substantially planar.
7. The method as defined in claim 1 wherein the combination of said basin containment portion and said screen are formed to encircle an internal body part.
8. The method as defined in claim 1 wherein the step of forming said screen is further defined by forming the number and size of the holes in said screen depending on one or more factors selected from a group including medicament solubility, medicament dissolution rate, and medicament concentration.
9. The method as defined in claim 1 further including the step of dividing said basin into at least two smaller basins.
10. The method as defined in claim 9 further including the step of forming the size and number of the holes in said screen covering said smaller basins.
11. A method of treating a disease within the eye of an animal, said method comprising the steps of:
- making an incision in the sclera;
- inserting a drug delivery device through said incision, said drug delivery device including: a basin containment portion including a basin constructed and arranged to contain the drug; a screen constructed and arranged to cover said basin and be affixed to said basin containment portion.
12. The method as defined in claim 11 the opposite sides of said basin is formed as a screen.
13. The method as defined in claim 11 wherein said basin passes through said basin containment portion and on the bottom of said basin is a second screen, said second screen being constructed and arranged to cover the basin and be affixed to said basin containment portion.
14. The method as defined in claim 11 wherein said basin containment portion is substantially planar.
15. The method as defined in claim 11 wherein said screen is substantially planar.
16. The method as defined in claim 13 wherein said second screen is substantially planar.
17. The method as defined in claim 11 wherein the size of the holes in said screen is dependent on one or more factors selected from a group including medicament solubility, medicament dissolution rate, and medicament concentration.
18. The method as defined in claim 13 wherein the number and size of the holes in said second screen is dependent on one or more factors selected from a group including medicament solubility, medicament dissolution rate, and medicament concentration.
19. The method as defined in claim 11 wherein said well in said basin containment portion is divided into at least two smaller basins.
20. The method as defined in claim 17 wherein the size and number of the holes in said screen covering said smaller basins are different.
Type: Application
Filed: Oct 8, 2009
Publication Date: Jan 28, 2010
Inventor: Theron Robert Rodstrom (Cranfills Gap, TX)
Application Number: 12/575,573
International Classification: A61F 9/007 (20060101); B23P 11/00 (20060101);