Ophthalmic devices for delivery of hydrophobic comfort agents
View Patent ↗The invention relates to a soft hydrogel contact lens, especially a silicone hydrogel contact lens, which has a capability of delivering a hydrophobic comfort agent into the eye of a wearer. The hydrophobic comfort agent includes without limitation a monoglyceride, a diglyceride, a triglyceride, a glycolipid, a glyceroglycolipid, a sphingolipid, a sphingo-glycolipid, a phospholipid, a fatty acid, a fatty alcohol, a hydrocarbon having a C 12 -C 28 chain in length, a mineral oil, a silicone oil, or a mixture thereof. It can be released from the soft hydrogel contact lens into the eye of a wearer when being worn so as to strengthen and stabilize the tear film lipid layer and alleviate the dryness of the eye.
1. A silicone hydrogel contact lens, comprising:
a polymeric matrix and a hydrophobic comfort agent which is not covalently linked to the polymer matrix but distributed therein and which is a building material for the tear film lipid layer of eyes, wherein the polymeric matrix comprises hydrophobic units derived from a silicone-containing monomer or macromer and hydrophilic units derived from a hydrophilic monomer or macromer,
wherein the hydrophobic comfort agent is a phospholipid,
wherein the silicone hydrogel contact lens has an oxygen permeability of at least about 40 barrers, an elastic modulus of from about 0.2 MPa to about 2.0 MPa, and a water content of from about 15% to about 70% by weight when fully hydrated,
wherein the silicone hydrogel contact lens is characterized by its capability of gradually releasing the hydrophobic comfort agent from the polymer matrix into the eye of a wearer over at least about 4 hours after the silicone hydrogel contact lens has been stored in a packaging solution for at least about one month and when being worn by the wearer.
2. The silicone hydrogel contact lens of claim 1 , wherein the soft hydrogel contact lens further has at least one property selected from the group consisting of an Ionoflux Diffusion Coefficient, D, of at least about 1.5×10 −6 mm 2 /min, a surface hydrophilicity characterized by having an averaged water contact angle of about 90 degrees or less, and combination thereof.
3. The silicone hydrogel contact lens of claim 2 , wherein the silicone hydrogel contact lens further comprises a non-crosslinkable hydrophilic polymer as a leachable wetting agent.
4. The silicone hydrogel contact lens of claim 3 , wherein the non-crosslinkable hydrophilic polymer is: a polyvinylalcohol; polyethylene oxide; a polyethylene-polypropylene block copolymer; a polyamide; a polyimide; a polylactone; polyvinylpyrrolidone; a copolymer of N-vinylpyrrolidone and one or more hydrophilic vinylic monomers; a homopolymer of acrylamide or methacrylamide; a copolymer of acrylamide or methacrylamide with one or more hydrophilic vinylic monomers; a homopolymer of N-vinyl formamide, N-vinyl acetamide, N-vinyl isopropylamide, or N-vinyl-N-methyl acetamide; a copolymer of N-vinyl formamide, N-vinyl acetamide, N-vinyl isopropylamide, or N-vinyl-N-methyl acetamide with one or more hydrophilic vinylic monomers, and a mixture thereof.
5. The silicone hydrogel contact lens of claim 1 , wherein the phospholipid is phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol, sphingomyelin, or a mixture thereof.