Packaging Solutions
A packaging system for the storage of a hydrogel contact lens employs an aqueous solution including hydroxypropyl methylcellulose.
This application claims benefit of Provisional Patent Application No. 60/989,485 filed Nov. 21, 2007 which is incorporated by reference herein.
BACKGROUND OF THE INVENTION1. Technical Field
The present invention generally relates to packaging solutions for contact lenses.
2. Description of Related Art
Blister-packs and glass vials are typically used to individually package each soft contact lens for sale to a customer. Saline or deionized water is commonly used to store the lens in the blister-packs, as mentioned in various patents related to the packaging or manufacturing of contact lenses. Because lens material may tend to stick to itself and/or to the lens package, packaging solutions for blister-packs have sometimes been formulated to reduce or eliminate lens folding and sticking. Additionally, polymeric components have been included in packaging solutions to improve comfort of a contact lens when worn. As examples, polyvinyl alcohol (PVA) has been used in contact lens packaging solutions, and U.S. Pat. No. 6,440,366 discloses contact lens packaging solutions comprising polyethylene oxide (PEO)/polypropylene oxide (PPO) block copolymers, especially poloxamers or poloxamines.
It is highly desirable that contact lenses be as comfortable as possible for wearers. Some contact lens wearers experience dryness or eye irritation throughout the day and particularly towards the end of the day. Some contact lens wearers experience discomfort when the lens is initially inserted in the eye.
A drawback to some polymeric components for contact lens packaging solutions is that the polymeric component may affect visual acuity. For example, especially at initial insertion of the lens, a wearer may experience blurred vision.
Accordingly, it would be desirable to provide a packaging system for contact lenses such that the lenses would be more comfortable to wear, without compromising visual acuity.
SUMMARY OF THE INVENTIONThis invention provides an aqueous solution for the packaging and storage of a contact lens. The packaging solution comprises hydroxypropyl methylcellulose (HPMC) and has an osmolality of at least about 200 mOsm/kg and a pH in the range of about 6 to about 8.
This invention also provides a method comprising: (a) immersing a contact lens in a package with the aqueous solution comprising hydroxypropyl methylcellulose; (b) sealing the solution and the contact lens within the package; and (c) sterilizing the packaged solution and device. The method may include hermetically sealing the contact lens and the solution in the package and heat sterilizing the package contents.
Additionally, this invention provides a combination comprising a contact lens and an aqueous solution in a sealed container, wherein the solution comprises hydroxypropyl methylcellulose and the solution has an osmolality of at least about 200 mOsm/kg and a pH in the range of 6 to 8.
The contact lens is preferably a silicone hydrogel contact lens, and may be made of an ionic copolymeric material, including a Group III or IV contact lens.
The solution preferably has a viscosity in the range of 0.5 to 5 cps. According to preferred embodiments, the solution has an osmolality in the range of 250 to 400 mOsm/kg, a pH in the range of 7.0 to 7.5, and/or a viscosity in the range of 1 to 3 cps.
According to preferred embodiments, the concentration of HPMC is 0.05 to 5 weight percent, more preferably 0.1 to 0.4 weight percent. According to preferred embodiments, the hydroxypropyl methylcellulose has a viscosity (at 20oC and at 2 weight % in water) of no greater than 50 cps, more preferably no greater than 25 cps.
The solution may further comprise a buffer, such as a borate buffer, and NaCl. The solution preferably does not contain an effective disinfecting amount of a disinfecting agent or a germicide compound.
The solution may consist essentially of hydroxypropyl methylcellulose, a borate buffer and NaCl.
The solution may consist of hydroxypropyl methylcellulose, a buffer, NaCl, water, and an optional chelating agent. A preferred embodiment is a solution consisting of: 0.05 to 0.5 weight percent hydroxypropyl methylcellulose; 0.05 to 2.5 weight percent buffer; 0.01 to 2.5 weight percent NaCl; 0 to 1 weight percent chelating agent; and water.
Another preferred embodiment is a solution comprising: 0.05 to 0.5 weight percent hydroxypropyl methylcellulose; 0.05 to 2.5 weight percent buffer; and 0.01 to 2.5 weight percent NaCl; and the solution has an osmolality in the range of 250 to 400 mOsm/kg, a pH in the range of 7.0 to 7.5, and a viscosity in the range of 1 to 3 cps.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTSThe present invention provides a packaging system for the storage of contact lenses. These lenses can provide optical correction, wound care, drug delivery, diagnostic functionality or cosmetic enhancement or effect or a combination of these properties. The invention is applicable to soft, hydrogel contact lenses. As is understood by one skilled in the art, a lens is considered to be “soft” if it can be folded back upon itself without breaking. The invention is applicable to all hydrogel contact lenses, and especially contact lenses made of an ionic material in US FDA Group III or IV. Group IV contact lenses are composed of at least 50 weight percent water when hydrated and are made of an ionic material. Group III contact lenses have a lower water content but are also made of an ionic material. Group I and II contact lenses, in contrast, are made of a non-ionic material. Additionally, the invention is especially applicable to silicone hydrogel contact lenses, especially silicone hydrogel contact lenses in Group III or IV.
Any hydrogel material known to produce contact lenses can be used herein. Hydrogels in general are a well-known class of materials that comprise hydrated, cross-linked polymeric systems containing water in an equilibrium state. Hydrogels generally have a water content greater than about 5 weight percent and more commonly between about 10 to about 80 weight percent. Hydrogels are generally prepared by polymerizing a monomeric mixture including at least one hydrophilic monomer; either one of the hydrophilic monomers functions as a crosslinking agent, or a separate crosslinking monomer may be employed in this monomeric mixture. (A crosslinker, crosslinking agent or crosslinking monomer is defined as a monomer having multiple polymerizable functionalities.) For ionic hydrogels, the initial monomeric mixture includes at least one ionic lens-forming monomer. Silicone hydrogels are specific class of hydrogel materials which are usually prepared by polymerizing a monomeric mixture containing at least one silicone-containing monomer and at least one hydrophilic monomer; either the silicone-containing monomer or the hydrophilic monomer functions as a crosslinking agent, or a separate crosslinking monomer may be employed.
Suitable hydrophilic monomers include: amides such as dimethylacrylamide and dimethylmethacrylamide; cyclic lactams such as n-vinyl-2-pyrrolidone; poly(alkylene glycols) functionalized with polymerizable groups; carboxylic acids such as methacrylic acid, acrylic acid and N-vinyloxycarbonylanaline; and hydroxyalkyl monomers, such as 2-hydroxyethyl methacrylate; and oxazolone monomers, including those disclosed in U.S. Pat. No. 4,910,277. Other suitable hydrophilic monomers will be apparent to one skilled in the art. The carboxylic acid-containing monomers are examples of ionic, hydrophilic lens-forming monomers.
Applicable silicone-containing monomeric units for use in the formation of silicone hydrogels are well known in the art and numerous examples are provided in U.S. Pat. Nos. 4,136,250; 4,153,641; 4,740,533; 5,034,461; 5,070,215; 5,260,000; 5,310,779, and 5,358,995.
Representative examples of applicable silicone-containing monomeric units include bulky polysiloxanylalkyl(meth)acrylic monomers. An example of a bulky polysiloxanylalkyl(meth)acrylic monomer is represented by the structure of Formula I:
wherein X denotes —O— or —NR—; each R1 independently denotes hydrogen or methyl; each R2 independently denotes a lower alkyl radical, phenyl radical or a group represented by
wherein each R2 independently denotes a lower alkyl or phenyl radical; and h is 1 to 10.
Examples of bulky monomers are methacryloxypropyl tris(trimethyl-siloxy)silane or tris(trimethylsiloxy)silylpropyl methacrylate, sometimes referred to as TRIS and tris(trimethylsiloxy)silylpropyl vinyl carbamate, sometimes referred to as TRIS-VC and the like.
Such bulky monomers may be copolymerized with a silicone macromonomer, which is a poly(organosiloxane) capped with an unsaturated group at two or more ends of the molecule. U.S. Pat. No. 4,153,641 discloses, for example, various unsaturated groups such as acryloxy or methacryloxy groups.
Another class of representative silicone-containing monomers includes, but is not limited to, silicone-containing vinyl carbonate or vinyl carbamate monomers such as, for example, 1,3-bis[4-vinyloxycarbonyloxy)but-1-yl]tetramethyl-disiloxane; 3-(trimethylsilyl)propyl vinyl carbonate; 3-(vinyloxycarbonylthio)propyl-[tris(trimethylsiloxy)silane]; 3-[tris(trimethylsiloxy)silyl]propyl vinyl carbamate; 3-[tris(trimethylsiloxy)silyl]propyl allyl carbamate; 3-[tris(trimethylsiloxy)silyl]propyl vinyl carbonate; t-butyldimethylsiloxyethyl vinyl carbonate; trimethylsilylethyl vinyl carbonate; trimethylsilylmethyl vinyl carbonate and the like and mixtures thereof.
Another class of silicone-containing monomers includes polyurethane-polysiloxane macromonomers (also sometimes referred to as prepolymers), which may have hard-soft-hard blocks like traditional urethane elastomers. They may be end-capped with a hydrophilic monomer such as 2-hydroxyethyl methacrylate (HEMA). Examples of such silicone urethanes are disclosed in a variety or publications, including U.S. Pat. No. 6,858,218 and PCT Published application Ser. No. WO 96/31792, which disclosures are hereby incorporated by reference in their entirety. Further examples of silicone urethane monomers are represented by Formulae II and III:
E(*D*A*D*G)a*D*A*D*E′; or (II)
E(*D*G*D*A)a*D*A*D*E′; or (III)
wherein:
D independently denotes an alkyl diradical, an alkyl cycloalkyl diradical, a cycloalkyl diradical, an aryl diradical or an alkylaryl diradical having 6 to about 30 carbon atoms;
G independently denotes an alkyl diradical, a cycloalkyl diradical, an alkyl cycloalkyl diradical, an aryl diradical or an alkylaryl diradical having 1 to about 40 carbon atoms and which may contain ether, thio or amine linkages in the main chain;
* denotes a urethane or ureido linkage;
a is at least 1;
A independently denotes a divalent polymeric radical of Formula IV:
wherein each RS independently denotes an alkyl or fluoro-substituted alkyl group having 1 to about 10 carbon atoms which may contain ether linkages between the carbon atoms; m′ is at least 1; and p is a number that provides a moiety weight of about 400 to about 10,000;
each of E and E′ independently denotes a polymerizable unsaturated organic radical represented by Formula V:
wherein: R3 is hydrogen or methyl;
R4 is hydrogen, an alkyl radical having 1 to 6 carbon atoms, or a —CO—Y—R6 radical wherein Y is —O—, —S— or —NH—;
R5 is a divalent alkylene radical having 1 to about 10 carbon atoms;
R6 is a alkyl radical having 1 to about 12 carbon atoms;
X denotes —CO— or —OCO—;
Z denotes —O— or —NH—;
Ar denotes an aromatic radical having about 6 to about 30 carbon atoms;
w is 0 to 6; x is 0 or 1; y is 0 or 1; and z is 0 or 1.
A specific example of a silicone-containing urethane monomer is represented by Formula VI:
wherein m is at least 1 and is preferably 3 or 4, a is at least 1 and preferably is 1, p is a number which provides a moiety weight of about 400 to about 10,000 and is preferably at least about 30, R7 is a diradical of a diisocyanate after removal of the isocyanate group, such as the diradical of isophorone diisocyanate, and each E″ is a group represented by:
In another embodiment of the present invention, a silicone hydrogel material comprises (in bulk, that is, in the monomer mixture that is copolymerized) about 5 to about 50 percent, and preferably about 10 to about 25, by weight of one or more silicone macromonomers, about 5 to about 75 percent, and preferably about 30 to about 60 percent, by weight of one or more polysiloxanylalkyl (meth)acrylic monomers, and about 10 to about 50 percent, and preferably about 20 to about 40 percent, by weight of a hydrophilic monomer, wherein at least one of the hydrophilic monomers is an ionic monomer.
The above silicone materials are merely exemplary, and other materials for use as substrates that can benefit by being packaged in the packaging solution according to the present invention and have been disclosed in various publications and are being continuously developed for use in contact lenses and other medical devices can also be used. For example, an ophthalmic lens for use herein can be a cationic lens such as a cationic contact lens or fluorinated silicone-containing monomers. Such monomers have been used in the formation of fluorosilicone hydrogels to reduce the accumulation of deposits on contact lenses made therefrom, as disclosed in, for example, U.S. Pat. Nos. 4,954,587; 5,010,141 and 5,079,319. The use of silicone-containing monomers having certain fluorinated side groups, i.e., —(CF2)—HH, have been found to improve compatibility between the hydrophilic and silicone-containing monomeric units. See, e.g., U.S. Pat. Nos. 5,321,108 and 5,387,662.
Contact lenses for application of the present invention can be manufactured employing various conventional techniques, to yield a shaped article having the desired posterior and anterior lens surfaces. Spincasting methods are disclosed in U.S. Pat. Nos. 3,408,429 and 3,660,545; static casting methods are disclosed in U.S. Pat. Nos. 4,113,224, 4,197,266, and 5,271,875.
Next, the lens will be immersed in a packaging solution and stored in a packaging system according to the present invention. Generally, a packaging system for the storage of a contact lens according to the present invention includes at least a sealed container containing an unused contact lenses immersed in an aqueous lens packaging solution. Preferably, the sealed container is a hermetically sealed blister-pack, in which a concave well containing a contact lens is covered by a metal or plastic sheet adapted for peeling in order to open the blister-pack. The sealed container may be any suitable generally inert packaging material providing a reasonable degree of protection to the lens, preferably a plastic material such as polyalkylene (e.g., polyethylene or polypropylene), PVC, polyamide, and the like.
The HPMC-containing packaging solution enhances initial and/or extended comfort when a contact lens, packaged in the solution and then removed from the packaging system, is placed on the eye for wearing. Any suitable HPMC may be employed in the packaging solution of this invention provided that it functions as described herein and has no substantial detrimental effect on the contact lens being stored or on the wearer of the contact lens. The HPMC and all other components of the packaging solution must be stable, soluble in aqueous solution, and compatible with one another, not only at room temperature, but also at temperatures of at least 120° C. for autoclaving conditions.
The packaging solutions of this invention have a pH in the range of 6 to 8 (at 25° C.), more preferably in the range of 7.0 to 7.5. The solutions have an osmolality of at least 200 mOsm/kg, more preferably in the range of 250 to 400 mOsm/kg, and most preferably in the range of 300 to 370 mOsm/kg. The packaging solutions have a viscosity within the range of 0.5 to 5 cps (or, mPa·s), more preferably in the range of 1 to 3 cps. It was found that if the packaging solution has too high viscosity, blurred vision may result when the contact lens coated with the solution is inserted in the eye. It was found that if the packaging solution has too low viscosity, no improvement in comfort results when the contact lens is inserted in the eye.
The HPMC is included in the solution at 0.05 to 0.5 weight percent, more preferably at 0.1 to 0.4 weight percent. The HPMC used in the packaging solution has a viscosity (at 20° C., and a concentration of 2 weight percent in water) of no greater than 50 cps, and preferably no greater than 25 cps. Accordingly, HPMC frequently marketed as “low viscosity” grades are preferred for this invention. These grades of HPMC typically having Mn no greater 20,000. It was found that relatively low viscosity HPMC, in amounts no greater than 0.5 weight percent, provided solutions with the desired improvement in comfort for initial insertion of the contact lens, but without deleteriously affecting visual acuity, contact lens dimensions, or stability of the packaging solution. In contrast, higher viscosity HPMC, in amounts necessary to improve comfort of the contact lens packaged therein, may tend to gel when autoclaved for sterilization, or may be difficult to filter in the sterile environment required for contact lens packaging.
The packaging solutions include a buffer, in an amount to maintain the pH of the solution in the desired range. Suitable buffers include: phosphate; borate; citrate; carbonate; tris-(hydroxymethyl)aminomethane (TRIS); bis(2-hydroxyethyl)-imino-tris-(hydroxymethyl)aminoalcohol (bis-tris); zwitterionic buffers such as N-[2-Hydroxy-1,1-bis(hydroxymethyl)ethyl]glycine (Tricine)and N-[2-Hydroxy-1,1-bis(hydroxymethyl)ethyl]glycine, MOPS; N-(Carbamoylmethyl)taurine (ACES); amino acids and amino acid derivatives; and mixtures thereof. Generally, buffers will be used in amounts ranging from about 0.05 to about 2.5 percent by weight, and preferably from about 0.1 to about 1.5 percent by weight of the solution. A preferred buffer is borate buffer, comprising sodium borate and/or boric acid as the buffering agent. Optionally, minor amounts of a base (such as NaOH) or an acid (such as HCl) may be included, if necessary, to make minor adjustments to the pH. To the extent such acids or bases are used in conjunction with the aforementioned buffering agents to adjust pH, these acids and bases are included within the term “buffer” and like terms.
The solutions include a tonicity agent, in an amount to maintain the osmotic pressure in the desired range. The solutions are made substantially isotonic with physiological saline, used alone or in combination with other tonicity adjusting agents. Examples of suitable tonicity adjusting agents include: sodium and potassium chloride, dextrose, calcium and magnesium chloride and the like and mixtures thereof. These agents are typically used individually in amounts ranging from about 0.01 to about 2.5 percent by weight, and preferably from about 0.2 to about 1.5%.
Various other materials may be included in the packaging system.
A surfactant may be included in the aqueous solution. Preferred are non-ionic surfactants, especially block copolymers of PEO and PPO. This class includes poloxamers and poloxamines, including those disclosed in U.S. Pat. No. 6,440,366. When present, the surfactant is employed at a concentration from about 0.01 to about 10% w/w and preferably from about 0.5 to about 1.5% w/w.
A chelating agent may be included in the aqueous solution. Agents include disodium ethylene diamine tetraacetate, alkali metal hexametaphosphate, citric acid, sodium citrate, 1-hydroxyethylidene-1,1,-diphosphonic acid, and the like, and mixtures thereof. When present, the chelating agent is preferably used in an amount of 0.001 to 10% w/w, more preferably 0.03 to 1% w/w.
An antioxidant may be included in the aqueous solution. Agents includesodium metabisulfite, sodium thiosulfate, N-acetylcysteine, butylated hydroxyanisole, butylated hydroxytoluene and the like and mixtures thereof.
The packaging solutions according to the present invention are physiologically compatible. Specifically, the solution must be “ophthalmically safe” for use with a lens such as a contact lens, meaning that a contact lens treated with the solution is generally suitable and safe for direct placement on the eye without rinsing, that is, the solution is safe and comfortable for daily contact with the eye via a contact lens that has been wetted with the solution. An ophthalmically safe solution has a tonicity and pH that is compatible with the eye and includes materials, and amounts thereof, that are non-cytotoxic according to ISO standards and U.S. Food & Drug Administration (FDA) regulations. The solution should be sterile in that the absence of microbial contaminants in the product prior to release must be statistically demonstrated to the degree necessary for such products. The liquid media useful in the present invention are selected to have no substantial detrimental effect on the lens being treated or cared for and to allow or even facilitate the present lens treatment or treatments. The liquid media are aqueous-based. A particularly useful aqueous liquid medium is that derived from saline, for example, a conventional saline solution or a conventional buffered saline solution.
The method of packaging and storing an ophthalmic lens according to the present invention includes at least packaging the ophthalmic lens immersed in the aqueous contact lens packaging solution described above. The method may include immersing the ophthalmic lens in an aqueous contact lens solution prior to delivery to the customer/wearer, directly following manufacture of the contact lens. Alternately, the packaging and storing in the solution of the present invention may occur at an intermediate point before delivery to the ultimate customer (wearer) but following manufacture and transportation of the lens in a dry state, wherein the dry lens is hydrated by immersing the lens in the contact lens packaging solution. Consequently, a package for delivery to a customer may include a sealed container containing one or more unused contact lenses immersed in an aqueous contact lens packaging solution according to the present invention.
In one embodiment, the steps leading to the present ophthalmic device packaging system include (1) molding an ophthalmic device in a mold comprising at least a first and second mold portion, (2) removing the lens from the mold portions; (3) introducing the packing solution of this invention and the ophthalmic lens into the container, and (4) sealing the container. Preferably, the method also includes the step of sterilizing the contents of the container. Sterilization may take place prior to, or most conveniently after, sealing of the container and may be effected by any suitable method known in the art, e.g., by balanced autoclaving of the sealed container at temperatures of about 120° C. or higher. Preferred packages are plastic blister packages, including a recess for receiving a contact lens and the package solution, where the recess is sealed with lidstock prior to sterilization of the package contents.
The following examples are provided to enable one skilled in the art to practice the invention and are merely illustrative of the invention. The examples should not be read as limiting the scope of the invention as defined in the claims.
EXAMPLEThe packaging solutions in Table 1 are prepared by the following general procedure. Purified water is heated to at least 70° C. NaCl and buffering agents are added with agitation. The HPMC is added in increments with agitation. After complete dissolution, the solution is brought to room temperature, and at this point, minor amounts of NaCl or NaOH may be added for final pH adjustment. Additional water is added to final volume (Q.S.). The HPMC is Table 1 is Methocel E15LV (trademark Dow Chemical), having a viscosity (as measured at 20° C., 2% concentration in water) of about 12.
Contact lens blister packages, each containing a balafilcon A contact lens (sold under the trademark PureVision, Bausch & Lomb Incorporated), are provided. Balafilcon A is a Group III, silicone hydrogel contact lens. Composition 1 or Composition 2 is added to the package so as to immerse the contact lens therein, and the package is sealed with lidstock. The sealed packages are sterilized by autoclaving at 121° C.
As a control, balafilcon A contact lenses were provided, packaged in borate buffer saline, at a similar pH and osmolality, but lacking HPMC. The control lenses, and the test lenses packaged in Composition 1 of this Example, were tested in a one day dispensing clinical. The test lens eyes exhibited statistically significant better forced choice preference for comfort at insertion compared to the control lens eyes. Forced choice denotes the wearer is asked to state a preference for either the control or the test lens. There were no statistically significant differences noted between the test and control lenses with respect to movement, inferior overlap, horizontal decentration, comfort, sting/burn, handling, normalized visual acuity, deposition, wettability, normalized corneal and conjunctival staining severity, and forced choice preference for comfort at end of day.
Packaging solutions in Table 2 include a chelating agent, and may be prepared according to the general procedure, supra. HAP denotes 1-hydroxyethylidene-1,1,-diphosphonic acid, and EDTA denotes disodium ethylene diamine tetraacetate.
It will be understood that various modifications may be made to the embodiments disclosed herein. Therefore the above description should not be construed as limiting, but merely as exemplifications of preferred embodiments. For example, the functions described above and implemented as the best mode for operating the present invention are for illustration purposes only. Other arrangements and methods may be implemented by those skilled in the art without departing from the scope and spirit of this invention. Moreover, those skilled in the art will envision other modifications within the scope and spirit of the features and advantages appended hereto.
Claims
1. A method comprising:
- (a) immersing a contact lens in a package with an aqueous solution comprising hydroxypropyl methylcellulose, wherein the solution has an osmolality of at least about 200 mOsm/kg and a pH in the range of 6 to 8;
- (b) sealing the solution and the contact lens within the package; and
- (c) sterilizing the packaged solution and device.
2. The method of claim 1, wherein the contact lens is a silicone hydrogel contact lens.
3. The method of claim 1, wherein the contact lens is a Group III or IV contact lens.
4. The method of claim 1, wherein the solution has a viscosity in the range of 0.5 to 5 cps.
5. The method of claim 1, wherein the solution has an osmolality in the range of 250 to 400 mOsm/kg, a pH in the range of 7.0 to 7.5, and a viscosity in the range of 1 to 3 cps.
6. The method of claim 1, wherein the concentration of hydroxypropyl methylcellulose is 0.05 to 5 weight percent.
7. The method of claim 1, wherein the concentration of hydroxypropyl methylcellulose is 0.1 to 0.4 weight percent.
8. The method of claim 1, wherein the hydroxypropyl methylcellulose has a viscosity (at 20 oC and at 2 weight % in water) of no greater than 50 cps.
9. The method of claim 1, wherein the hydroxypropyl methylcellulose has a viscosity (at 20 oC and at 2 weight % in water) of no greater than 25 cps.
10. The method of claim 1, wherein the solution comprises a buffer and NaCl.
11. The method of claim 10, wherein the solution comprises a borate buffer.
12. The method of claim 1, including hermetically sealing the contact lens and the solution in the package and heat sterilizing the package contents.
13. The method of claim 1, wherein the solution does not contain an effective disinfecting amount of a disinfecting agent or a germicide compound.
14. A combination comprising a contact lens and an aqueous solution in a sealed container, wherein the solution comprises hydroxypropyl methylcellulose and the solution has an osmolality of at least about 200 mOsm/kg and a pH in the range of 6 to 8.
15. The combination of claim 14, wherein the contact lens is a silicone hydrogel contact lens.
16. The combination of claim 14, wherein the solution consists essentially of hydroxypropyl methylcellulose, a borate buffer and NaCl.
17. The combination of claim 14, wherein the solution consists of hydroxypropyl methylcellulose, a buffer, NaCl, water, and an optional chelating agent.
18. The combination of claim 14, wherein the solution consists of: 0.05 to 0.5 weight percent hydroxypropyl methylcellulose; 0.05 to 2.5 weight percent buffer; 0.01 to 2.5 weight percent NaCl; 0 to 1 weight percent chelating agent; and water.
19. The combination of claim 15, wherein the solution comprises: 0.05 to 0.5 weight percent hydroxypropyl methylcellulose; 0.05 to 2.5 weight percent buffer; and 0.01 to 2.5 weight percent NaCl; and the solution has an osmolality in the range of 250 to 400 mOsm/kg, a pH in the range of 7.0 to 7.5, and a viscosity in the range of 1 to 3 cps.
20. The combination of claim 19, wherein the hydroxypropyl methylcellulose has a viscosity (at 20 oC and at 2 weight % in water) of no greater than 25 cps.
Type: Application
Filed: Oct 27, 2008
Publication Date: May 21, 2009
Inventors: Sanjay M. Rastogi (Rochester, NY), Susan E. Burke (Batavia, NY), Thomas Menzel (Rochester, NY)
Application Number: 12/258,938
International Classification: B65B 55/02 (20060101); B65B 1/04 (20060101); A45C 11/04 (20060101);
