Method for applying stable coating on silicone hydrogel contact lenses
First Claim
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1. A method for producing coated silicone hydrogel contact lenses each having a durable crosslinked hydrophilic coating thereon, comprising the steps of:
- (1) introducing a polymerizable composition into a lens mold, wherein the polymerizable composition comprises(a) at least silicone-containing polymerizable component which is at least one siloxane-containing vinylic monomer, at least one silicone-containing vinylic macromer, or a combination thereof,(b) at least one vinylic crosslinking agent,(c) a blending vinylic monomer, wherein the blending vinylic monomer is a C1-C10 alkyl (meth)acrylate, cyclopentylacrylate, cyclohexylmethacrylate, cyclohexylacrylate, isobornyl (meth)acrylate, styrene, 4,6-trimethylstyrene (TMS), t-butyl styrene (TBS), trifluoroethyl (meth)acrylate, hexafluoro-isopropyl (meth)acrylate, hexafluorobutyl (meth)acrylate, or combinations thereof, (d) from about 30% to about 60% by weight of at least one N-vinyl amide monomer relative to the total amount of polymerizable components, wherein said at least one N-vinyl amide monomer is N-vinylpyrrolidone, N-vinyl-N-methyl acetamide, N-vinyl acetamide, N-vinyl formamide, N-vinyl isopropylamide, or a mixture thereof, and(e) at least one free-radical initiator;
(2) curing thermally or actinically the polymerizable composition in the lens mold to form a silicone hydrogel contact lens;
(3) forming a stable base coating on the formed silicone hydrogel contact lens according to a water-based coating process which comprises(i) a substep of immersing the formed silicone hydrogel contact lens in an aqueous solution of a polyanionic polymer having carboxyl groups and a number average molecular weight of at least about 100000 Daltons for a time period of from about 60 minutes to about 240 minutes, wherein the aqueous solution has a pH of from about 0 to about 3.5, and(ii) a substep of rinsing the silicone hydrogel contact lens having the base coating thereon with a buffered saline having a pH from about 6.5 to about 9.5; and
(4) heating the rinsed silicone hydrogel contact lens having the stable base coating thereon in a packaging solution including a water-soluble, thermally-crosslinkable hydrophilic polymeric material at a temperature from about 60°
C. to about 140°
C. to form the durable crosslinked hydrophilic coating, wherein the packaging solution has a pH from about 6.8 to about 7.6 and a tonicity of from about 200 to about 450 milliosmol (mOsm), wherein the durable crosslinked hydrophilic coating exhibits a water-break-up-time (WBUT) of at least about 5 seconds, a friction rating of about 3 or lower, and a coating durability characterized by surviving a digital rubbing test,provided that after step (2) the silicone hydrogel contact lens is not in contact with any organic solvent other than propylene glycol and polyethylene glycol having a molecular weight of 400 Daltons or less to remove unpolymerized polymerizable components.
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Abstract
The present invention generally relates to a method for producing silicone hydrogel contact lenses having a stable lubricious coating thereon without involving use of organic solvent in post-curing processes.
558 Citations
22 Claims
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1. A method for producing coated silicone hydrogel contact lenses each having a durable crosslinked hydrophilic coating thereon, comprising the steps of:
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(1) introducing a polymerizable composition into a lens mold, wherein the polymerizable composition comprises (a) at least silicone-containing polymerizable component which is at least one siloxane-containing vinylic monomer, at least one silicone-containing vinylic macromer, or a combination thereof, (b) at least one vinylic crosslinking agent, (c) a blending vinylic monomer, wherein the blending vinylic monomer is a C1-C10 alkyl (meth)acrylate, cyclopentylacrylate, cyclohexylmethacrylate, cyclohexylacrylate, isobornyl (meth)acrylate, styrene, 4,6-trimethylstyrene (TMS), t-butyl styrene (TBS), trifluoroethyl (meth)acrylate, hexafluoro-isopropyl (meth)acrylate, hexafluorobutyl (meth)acrylate, or combinations thereof, (d) from about 30% to about 60% by weight of at least one N-vinyl amide monomer relative to the total amount of polymerizable components, wherein said at least one N-vinyl amide monomer is N-vinylpyrrolidone, N-vinyl-N-methyl acetamide, N-vinyl acetamide, N-vinyl formamide, N-vinyl isopropylamide, or a mixture thereof, and (e) at least one free-radical initiator; (2) curing thermally or actinically the polymerizable composition in the lens mold to form a silicone hydrogel contact lens; (3) forming a stable base coating on the formed silicone hydrogel contact lens according to a water-based coating process which comprises (i) a substep of immersing the formed silicone hydrogel contact lens in an aqueous solution of a polyanionic polymer having carboxyl groups and a number average molecular weight of at least about 100000 Daltons for a time period of from about 60 minutes to about 240 minutes, wherein the aqueous solution has a pH of from about 0 to about 3.5, and (ii) a substep of rinsing the silicone hydrogel contact lens having the base coating thereon with a buffered saline having a pH from about 6.5 to about 9.5; and (4) heating the rinsed silicone hydrogel contact lens having the stable base coating thereon in a packaging solution including a water-soluble, thermally-crosslinkable hydrophilic polymeric material at a temperature from about 60°
C. to about 140°
C. to form the durable crosslinked hydrophilic coating, wherein the packaging solution has a pH from about 6.8 to about 7.6 and a tonicity of from about 200 to about 450 milliosmol (mOsm), wherein the durable crosslinked hydrophilic coating exhibits a water-break-up-time (WBUT) of at least about 5 seconds, a friction rating of about 3 or lower, and a coating durability characterized by surviving a digital rubbing test,provided that after step (2) the silicone hydrogel contact lens is not in contact with any organic solvent other than propylene glycol and polyethylene glycol having a molecular weight of 400 Daltons or less to remove unpolymerized polymerizable components. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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Specification