Contact lens packaging solutions
View Patent ↗The present invention relates to improved contact lens products which not only have initial insertion comfort. The contact lens product of the invention comprises a soft hydrogel contact lens immersed and autoclaved in a packaging solution including a low molecular weight polyethylene glycol (PEG) (or glycerin) and a homopolymer or copolymer of vinylpyrrolidone. The present invention also provides methods for making contact lens products of the invention.
1. A process for making a soft contact lens capable of easing wearer's initial discomfort, comprising the steps of:
a) packaging a hydrogel contact lens in a container containing a packaging solution, wherein the packaging solution comprises
(1) copolymer of vinylpyrrolidone and at least one amino-containing vinylic monomer, wherein the amino-containing vinylic monomer is selected from the group consisting of alkylaminoalkylmethacrylate having 8-15 carbon atoms, alkylaminoalkylacrylate having 7-15 carbon atoms, dialkylaminoalkylmethacrylate having 8-20 carbon atoms, dialkylaminoalkylacrylate having 7-20 carbon atoms, and N-vinylalkylamide having 3-10 carbon atoms,
(2) glycerin or a polyethylene glycol having an average molecular weight of about 600 or less,
(3) an α-oxo-multi-acid or salt thereof in an amount sufficient to have a reduced susceptibility to oxidation degradation of the polyethylene glycol in the packaging solution, and
(4) one or more buffering agents in an amount sufficient to provide the solution a pH of from about 6.0 to 8.0,
wherein the copolymer of vinylpyrrolidone is present in an amount sufficient to provide the packaging solution a viscosity of up to about 5.0 centipoises at 25° C., wherein the copolymer of vinylpyrrolidone has a molecular weight sufficiently large to form a cushion layer on the soft hydrogel contact lens, wherein the packaging solution has an osmolality of from about 200 to about 450 mOsm/kg; and
b) sterilizing the hydrogel contact lens in the package to obtain the soft contact lens.
2. The process of claim 1 , wherein the amino-containing vinylic monomer is dialkylaminoalkylmethacrylate having 8-20 carbon atoms or dialkylaminoalkylacrylate having 7-20 carbon atoms.
3. The process of claim 1 , wherein the hydrogel contact lens is a silicone hydrogel contact lens.
4. The process of claim 1 , wherein the amino-containing vinylic monomer is dimethylaminoethylmethacrylate or dimethylaminoethylacrylate.
5. The process of claim 1 , wherein the packaging solution has a viscosity of up to about 3.0 centipoises at 25° C.
6. The process of claim 1 , wherein the packaging solution comprises a polyethylene glycol having an average molecular weight of about 600 or less.
7. The process of claim 1 , wherein the α-oxo-multi-acid is selected from the group consisting of citric acid, 2-ketoglutaric acid, and malic acid.
8. The process of claim 1 , wherein the α-oxo-multi-acid is citric acid.
9. The process of claim 1 , wherein hydrogel contact lens includes one or more leachable lubricant therein.