Method of Packaging a Lens
A contact lens package includes a sealed receptacle containing a contact lens immersed in a sterile solution. The contact lens is made of a silicone hydrogel copolymer, and the solution includes a stabilizing agent in an amount effective to inhibit changes in physical properties of the silicone hydrogel copolymer.
1 . A contact lens package including a sealed receptacle containing a contact lens immersed in a sterile solution, wherein the contact lens is made of a silicone hydrogel copolymer, and the solution comprises a stabilizing agent in an amount effective to inhibit changes in physical properties of the silicone hydrogel copolymer.
2 . The package of claim 1 , wherein the silicone hydrogel copolymer is ionic.
3 . The package of claim 2 , wherein the silicone hydrogel copolymer is anionic.
4 . The package of claim 2 , wherein the silicone hydrogel copolymer is cationic.
5 . The package of claim 2 , wherein the stabilizing agent is an amine that complexes with anionic groups of the copolymer.
6 . The package of claim 5 , wherein the stabilizing agent is selected from the group consisting of: amino hydrocarbons; amino alcohols; and amino acids.
7 . The package of claim 3 , wherein the stabilizing agent is a quaternary ammonium-containing compound that forms an ionic complex with anionic groups of the copolymer.
8 . The package of claim 4 , wherein the stabilizing agent includes anionic groups that complex with the cationic groups of the copolymer.
9 . The package of claim 2 , wherein the stabilizing agent contains groups that hydrogen bond with the ionic groups of the copolymer.
10 . The package of claim 9 , wherein the stabilizing agent is selected from the group consisting of: poly(vinylpyrrolidinone)s; poly(ethylene glycol)s; poly(vinyl alcohol)s; poly(propylene glycol)s; saccharides; and polyhydric alcohols.
11 . The package of claim 1 , wherein the silicone hydrogel copolymer is the polymerization product of a monomeric mixture comprising: a silicone-containing crosslinking monomer; and a hydrophilic monomer.
12 . The package of claim 11 , wherein the silicone hydrogel copolymer is the polymerization product of a monomeric mixture comprising: the silicone-containing crosslinking monomer; the hydrophilic monomer; and a monofunctional silicone-containing monomer.
13 . The package of claim 2 , wherein the silicone hydrogel copolymer is the polymerization product of a monomeric mixture comprising: a silicone-containing monomer; a hydrophilic monomer; and an ionic monomer.
14 . The package of claim 13 , wherein the ionic monomer comprises a cationic monomer, and the stabilizing agent is selected from the group consisting of MOPS, tromethamine, diglycine, and mixtures thereof.
15 . The package of claim 1 , wherein the solution has a pH of 6 to 8.
16 . The package of claim 1 , wherein the solution lacks an antimicrobial agent.
17 . The package of claim 1 , wherein the solution comprises 0.02 to 5.0 weight percent of the stabilizing agent.
18 . The package of claim 1 , wherein lidstock is sealed over the receptacle containing the solution and the contact lens.
19 . The package of claim 18 , wherein the lidstock is sealed around a perimeter of the receptacle.
20 . The package of claim 18 , wherein the solution and the contact lens are subjected to thermal energy while sealed in the package receptacle.
21 . The package of claim 20 , wherein the solution and the contact lens are heated to a temperature of at least 100° C.
22 . The package of claim 18 , wherein the solution and the contact lens are sterilized while sealed in the package receptacle.
23 . The package of claim 1 , wherein the package containing the solution and the contact lens is autoclaved.
24 . The package of claim 1 , wherein the stabilizing agent is in an amount effective to inhibit changes in modulus of the silicone hydrogel copolymer.
25 . A method comprising:
sealing a receptacle of a contact lens package that contains a solution and a contact lens, wherein the contact lens is made of a silicone hydrogel copolymer; and
storing the contact lens in the package for an extended period of time, wherein the stabilizing agent inhibits changes in physical properties of the silicone hydrogel copolymer during storage.
26 . A method of improving the hydrolytic stability of a contact lens made of a silicone hydrogel copolymer, comprising storing the contact lens in a sealed package and immersed in a sterile solution comprising a stabilizing agent, wherein the stabilizing agent inhibits changes in physical properties of the silicone hydrogel copolymer during storage.
27 . A method of increasing the shelf life of a contact lens made of a silicone hydrogel copolymer and contained in a sealed package, comprising storing the contact lens in the sealed package and immersed in a solution comprising a stabilizing agent that inhibits changes in physical properties of the silicone hydrogel copolymer during storage.
28 . A method of providing a silicone hydrogel contact lens with a shelf life of at least 3 years, comprising storing the contact lens in the sealed package and immersed in a solution comprising a stabilizing agent that inhibits changes in physical properties of the silicone hydrogel copolymer during storage.