Patent Application
20050006255
This invention related to packages for storing contact lenses as well as methods of using and preparing these packages.
Contact lenses have been used commercially to improve vision since the 1950s. At first contact lenses were made of hard materials, which were relatively easy to handle and package for use, but were uncomfortable for many patients. Later developments, gave rise to softer more comfortable lenses made of hydrophobic hydrogels, particularly silicone hydrogels. These lenses are very pliable, but due to this texture and their chemical composition, they present a number of problems with packaging.
Most contact lenses are packaged in individual blister packages having a bowl portion and a foil top, where the bowl portion is made from a hydrophobic material such as polypropylene. See U.S. Pat. Nos. 4,691,820; 5,054,610; 5,337,888; 5,375,698; 5,409,104; 5,467,868; 5,515,964; 5,609,246; 5,695,049; 5,697,495; 5,704,468; 5,711,416; 5,722,536; 5,573,108; 5,823,327; 5,704,468; 5,983,608; 6,029,808; 6,044,966; and 6,401,915 for examples of such packaging, all of which are hereby incorporated by reference in their entirety. While polypropylene is resilient enough to withstand the sterilization steps of contact lens manufacture, this material has an affinity for contact lenses made of silicone hydrogels. When silicone hydrogels are packaged in polypropylene bowls, the lenses stick to the bowl and cannot be removed from the package without damaging the pliable lenses. Therefore is a need to prepare a contact lens package that has resilient properties, but does not stick to the final product. It is this need that is met by the following invention.
This invention includes a package for storing medical devices in a solution comprising, consisting essentially of, or consisting of, a molded base wherein the molded base comprises an additive, provided that the medical device is not a contact lens consisting of acqualfilcon A coated with polyHema.
As used herein a “medical device” is any device that is stored or packaged in a solution and is used to treat a human disease. Examples of medical devices include but are not limited to ophthalmic devices that reside in or on the eye. Ophthalmic devices includes but are not limited to soft contact lenses, intraocular lenses, overlay lenses, ocular inserts, and optical inserts. These devices can provide optical correction or may be cosmetic. The preferred medical devices of the invention are soft contact lenses made from silicone elastomers or hydrogels, which include but are not limited to silicone hydrogels, and fluorohydrogels. Soft contact lens formulations are disclosed in U.S. patent application Ser. No. 60/318,536, entitled Biomedical Devices Containing Internal wetting Agents,” filed on Sep. 10, 2001 and its non-provisional counterpart of the same title, filed on Sep. 6, 2002, U.S. Pat. No. 5,710,302, WO 9421698, EP 406161, JP 2000016905, U.S. Pat. No. 5,998,498, U.S. patent application Ser. No. 09/532,943, U.S. Pat. No. 6,087,415, U.S. Pat. No. 5,760,100, U.S. Pat. No. 5,776, 999, U.S. Pat. No. 5,789,461, U.S. Pat. No. 5,849,811, and U.S. Pat. No. 5,965,631. The foregoing references are hereby incorporated by reference in their entirety. The particularly preferred medical devices of the invention are soft contact lenses made from etafilcon A, genfilcon A, lenefilcon A, polymacon, balafilcon A, lotrafilcon A. and silicone hydrogels as prepared in U.S. Pat. No. 5,998,498, U.S. patent application Ser. No. 09/532,943, a continuation-in-part of U.S. patent application Ser. No. 09/532,943, filed on Aug. 30, 2000, U.S. Pat. No. 6,087,415, U.S. Pat. No. 5,760,100, U.S. Pat. No. 5,776, 999, U.S. Pat. No. 5,789,461, U.S. Pat. No. 5,849,811, and U.S. Pat. No. 5,965,631. These patents as well as all other patent disclosed in this application are hereby incorporated by reference in their entirety. The more particularly preferred medical devices of the invention are soft contact lenses, balafilcon A, lotrafilcon A, galyfilcon A, senofilcon A, or those made as described in U.S. patent application Ser. No. 60/318,536, entitled Biomedical Devices Containing Internal wetting Agents,” filed on Sep. 10, 2001 and its non-provisional counterpart of the same title, filed on Sep. 6, 2002. The most particularly preferred medical devices are soft contact lenses made from either galyfilcon A or senofilcon A.
The term “molded base” refers to any polymer, rubber, or plastic that can be formed into a receptacle for medical devices, where the size and shape of the base are determined by the device and other considerations known those who are skilled in the art of making or designing molded bases. For example molded bases may be individual blister packages, secondary packages, or hydrating trays. The molded base may be prepared from any number of materials provided that those materials are compatible with the chemical and physical properties of the device. Examples of suitable materials include but are not limited to polypropylene, polyethylene, nylons, olefin co-polymers, acrylics, rubbers, urethanes, polycarbonates, or fluorocarbons. The preferred materials are metallocenes polymers and co-polymers made of polypropylene, polyethylene, having a melt flow range of about 15 g/10 minutes to about 44 g/10 minutes as determined by ASTM D-1238. With respect to the shape of the molded base, examples of suitably shaped bases are disclosed in the following patents which are hereby incorporated by reference in their entirety, U.S. Pat. Nos. D 458,023; 4,691,820; 5,054,610; 5,337,888; 5,375,698; 5,409,104; 5,467,868; 5,515,964; 5,609,246; 5,695,049; 5,697,495; 5,704,468; 5,711,416; 5,722,536; 5,573,108; 5,823,327; 5,704,468; 5,983,608; 6,029,808; 6,044,966; and 6,401,915. As in the cited references, the molded based is sealed about the cavity that encloses the contact lens. Flexible cover sheets can be made from can be an adhesive laminate of an aluminum foil and a polypropylene film or any other extruded or co-extruded film that can be sealed to the top surface of the flange in order to form a hermetic seal for the medical device and the solution. Further, the base can be formed by any of a number of known methods which include but are not limited to injection molding, transfer molding, skin packaging, blow molding, coinjection molding, film extrusion, or film co-extrusion.
As used herein the term “additive” refers to a substance that is added to the polymer, rubber, or plastic prior to forming the molded base, where the material inhibits sticking, adherence, or adhesion of the medical device to the molded base. The additive is mixed with the remainder of the molded base material and amount of additive present by weight percentage based on the total weight of the molded base material is greater than about 0.25 to about 10 weight percent, preferably greater than about 0.25 to about 5 weight percent, most preferably about 0.25 to about 3 weight percent. The preferred additives are glycerol monostearate (2%), polyvinylpyrolidone (1% to 5%), polyvinylpyrolidone/maleic anhydride (1/1% to 5/5%), and succinic acid (5%). Polyvinylpyrolidinone has a variety of molecular weight ranges (as indicated by the KD#) and consistencies (flake, powdered/micronized). When PVP KD90 is used as an additive, it is preferred that it is powered/micronized.
The term “solution” refers to any liquid medium in which a medical device is stored. The preferred solutions are aqueous solutions contain physiological buffers. The particularly preferred solution is saline solution.
For example, if the medical device is a contact lens, it is preferred that the molded base is transparent to the degree necessary to permit visual inspection, UV sterilization or both. The preferred additives are glycerol monostearate present at about 2 weight percent, succininc acid present at about 5 weight percent, PVP KD90 present at about 1-5 weight percent, PVP/maleic anhydride present at about 1/1 to about 5/5 weight percent. If the inner surface of the medical device has a roughness of about 0.2 μm to about 4.5 μm, the preferred additives are maleic anhydride or PVP/maleic anhydride, most preferably maleic anhydride.
Further, the invention includes a method of reducing the adherence of a medical device to its packaging, comprising, consisting essentially of, or consisting of, storing said medical device in a solution in a package comprising, consisting essentially of, or consisting of, a molded base wherein said molded base comprises an additive, provided that the medical device is not a contact lens consisting of acqualfilcon A coated with polyHema. The terms molded base, medical device, solution and additive all have their aforementioned meanings and preferred ranges.
When soft contact lenses are prepared, the lenses cured to a hard disc and subsequently hydrated with water to give the non-sterilized final product. During this hydration step, soft contact lenses often stick to the surface of the hydration chamber and it would useful to find a method of hydrating soft contact lenses which alleviates this problem.
To solve this problem, the invention includes a method of hydrating a contact lens comprising, consisting essentially of, or consisting of hydrating said lens in a molded base wherein said molded base comprises an additive. The terms molded base, medical device, solution and additive all have their aforementioned meanings. The preferred values for the medical device, the solution and the additive are as listed above. The preferred molded base is a square or a rectangle.
Other have tried to address the problem of a medical device adhering to its packaging. For example U.S. patent application Ser. No. 09/942,347, entitled “Textured Contact Lens Package,” filed on Aug. 29, 2001 and U.S. patent application Ser. No. 10/183,133, entitled “Contact Lens Packages, ” filed on Jun. 26, 2002 disclose solutions to this problem. The disclosure of these applications are hereby incorporated by reference in their entirety. Even though those methods address this problem, it is contemplated by the inventors of this patent application that the additives of this invention may be incorporated into the packaging of each of the cited references.
In order to illustrate the invention the following examples are included. These examples do not limit the invention. They are meant only to suggest a method of practicing the invention. Those knowledgeable in contact lenses as well as other specialties may find other methods of practicing the invention. However, those methods are deemed to be within the scope of this invention.
The following abbreviations are used below
Additives (identity and amounts listed in Table 1) were mixed with polypropylene (listed below). The material was injection molded to form the base portion of a contact lens package. The configuration of the package is as illustrated in FIG. 1 of U.S. Pat. No. 5,467,868 which is hereby incorporated by reference.
Contact lenses made from acquafilcon A coated with polyhema, a silicone hydrogel, were added to individual polypropylene blister packs having different additives containing 950 μL of saline solution and then the blister pack was heat sealed with an flexible cover. Lenses were visually evaluated for adhesion to the package after sterilization. The flexible cover sheet was removed and the molded base is rotated or jiggled without spilling the saline solution while a contact lens is observed to determine if it is adhered to the inner surface of the molded base. Lenses that do not adhere are free floating and pass the test. If the lenses adhere to the molded base in any manner they fail the test. The addtitive, its weight percentage, the number of lenses that stuck to the package, and number of lenses that were free floating are displayed in Table 1. This example illustrates that glycerol monostearate is a superior additive.
Packages containing 2% weight percent GMS and Exxon 1605 were prepared using the method of Example 1. Contact lenses of types A, B, and C were added to individual blister packages along with 950 μL of saline solution. The filed packages were heat sealed with flexible covers and sterilized. The packaged lenses were submitted to consumers. The consumers opened the packages and evaluated the lenses for ease of removal of the lens from the package using the following criteria and grading system
The testing methods and preparations of Example 1 were repeated with different additives and lens types as per Table 2. If “(UP)” appears in an entry, that bowl of the blister is shaped as in U.S. Pat. No. D 458,023. When the term “Rough Bowl” appears, the inside surface of the bowl is roughened to an Ra of 0.5 mm to 0.8 mm.
This application is a non-provisional filing of a provisional application, U.S. patent application Ser. No. 60/436,109, filed on Dec. 23, 2002.
| Number | Date | Country | |
|---|---|---|---|
| 60436109 | Dec 2002 | US |
