Silicone hydrogel ophthalmic devices molded in vinyl alcohol copolymer molds and related methods
View Patent ↗Silicone hydrogel ophthalmic devices, such as ocular inserts and contact lenses, formed in direct contact with molds comprising at least one vinyl alcohol copolymer and related methods are described. The at least one vinyl alcohol copolymer of the molds is a vinyl alcohol copolymer other than an ethylene-vinyl alcohol copolymer. The methods of manufacturing ophthalmic devices can use dry or wet demolding processes, or dry or wet delensing processes.
1. A method of manufacturing a silicone hydrogel ophthalmic device, comprising:
providing a polymerizable composition, the polymerizable composition comprising
(a) at least one siloxane monomer,
(b) at least one hydrophilic monomer, and
(c) at least one crosslinking agent;
polymerizing the polymerizable composition in an ophthalmic device mold assembly to form a polymeric ophthalmic device body, wherein at least one mold member of the ophthalmic device mold assembly comprises at least one vinyl alcohol copolymer which is not an ethylene-vinyl alcohol copolymer;
contacting the polymeric ophthalmic device body with a washing liquid to remove extractable material from the polymeric ophthalmic device body; and
packaging the polymeric ophthalmic device body in an ophthalmic device packaging solution in an ophthalmic device package.
2. The method of claim 1 , wherein the silicone hydrogel ophthalmic device is a silicone hydrogel contact lens, the ophthalmic device mold assembly is a contact lens mold assembly, the polymeric ophthalmic device body is a polymeric contact lens body, the ophthalmic device packaging solution is a contact lens packaging solution, and the ophthalmic device package is a contact lens package.
3. The method of claim 1 , wherein, following release of the polymeric device body from the mold assembly, a layer of the at least one vinyl alcohol copolymer is not present on a surface of the polymeric device body.
4. The method of claim 1 , wherein, following release of the polymeric device body from the mold assembly, the device body is present in a solution comprising the at least one vinyl alcohol copolymer.
5. The method of claim 1 , wherein the at least one vinyl alcohol copolymer comprises a highly amorphous vinyl alcohol copolymer having a level of crystallinity less than 35%.
6. The method of claim 1 , wherein the at least one vinyl alcohol copolymer comprises a water-soluble vinyl alcohol copolymer.
7. The method of claim 1 , further comprising the step of releasing the polymeric ophthalmic device body from the at least one mold member of the ophthalmic device mold assembly that comprises the at least one vinyl alcohol copolymer which is not an ethylene-vinyl alcohol copolymer, the step of releasing the device body from the at least one mold member comprising a wet demolding step, a wet delensing step, or a wet demolding and delensing step, wherein the wet demolding step, wet delensing step or wet demolding and delensing step results in the mold member comprising the at least one vinyl alcohol copolymer being at least partially dissolved.
8. The method of claim 1 , wherein the at least one siloxane monomer comprises a siloxane monomer having at least one acrylate polymerizable functional group.
9. The method of claim 1 , wherein the at least one siloxane monomer comprises a multi-functional monomer.
10. The method of claim 1 , wherein the at least one siloxane monomer comprises a siloxane monomer selected from:
a monofunctional siloxane monomers represented by formula (2):
where n of formula (2) is 0-30;
a bifunctional siloxane monomer represented by formula (3):
wherein n of formula (3) is an integer of about 100-150, m of formula (3) is an integer of about 5 to about 10, h is an integer of about 2 to 8, and p is an integer of 1 to 200;
a monofunctional siloxane monomer represented by formula (4):
wherein m of formula (4) represents one integer from 3 to 10, n of formula (4) represents one integer from 1 to 10, R 1 of formula (4) is an alkyl group having from 1 to 4 carbon atoms, and each R 2 of formula (4) is independently either a hydrogen atom or a methyl group; a bifunctional siloxane monomer represented by formula (5):
wherein R 1 of formula (5) is selected from either hydrogen atom or a methyl group; R 2 of formula (5) is selected from either of hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms; m of formula (5) represents an integer of from 0 to 10; n of formula (5) represents an integer of from 4 to 100; a and b represent integers of 1 or more; a+b is equal to 20-500; b/(a+b) is equal to 0.01-0.22; and the configuration of siloxane units includes a random configuration; a bifunctional siloxane monomer represented by formula (6):
wherein R3 is selected from either hydrogen atom or a methyl group, m of formula (6) represents an integer from 0 to 15, and n of formula (6) represents an integer from 1 to 500; and a bifunctional siloxane monomer represented by formula (7) having a molecular weight of about 4,500 to about 5,500:
11. The method of claim 1 , wherein the at least one siloxane monomer of the polymerizable composition comprises a siloxane monomer component comprising a first siloxane monomer and a second siloxane monomer having a different molecular weight than the at least one first siloxane monomer.
12. The method of claim 1 , wherein the at least one hydrophilic monomer comprises a vinyl amide-containing monomer.
13. The method of claim 1 , wherein the at least one hydrophilic monomer comprises a vinyl ether-containing monomer.
14. The method of claim 1 , wherein the at least one crosslinking agent comprises a vinyl-containing crosslinking agent.
15. The method of claim 1 , wherein the at least one mold member of the ophthalmic device mold assembly that comprises at least one vinyl alcohol copolymer which is not an ethylene-vinyl alcohol copolymer, is formed by injection molding.
16. The method of claim 1 , wherein the polymerizable composition further comprises at least one hydrophobic ethylene glycol methyl ether methacrylate-containing monomer.
17. The method of claim 1 , wherein the polymerizable composition further comprises a tinting agent, a UV-blocking agent, or both a tinting agent and a UV-blocking agent.
18. The method of claim 1 , wherein the at least one mold member of the ophthalmic device mold assembly comprising at least one vinyl alcohol copolymer which is not an ethylene-vinyl alcohol copolymer is formed by injection molding the at least one vinyl alcohol copolymer using a process setting selected from the group consisting of: melt temperature from about 180° C. to about 250° C., barrel temperature from about 180° C. to about 250° C., throat temperature from about 30° C. to about 70° C., mold tool temperature from about 30° C. to about 95° C., holding time from about 1 second to about 5 seconds, injection speed from about 50 mm/second to about 250 mm/second, plasticizing speed from about 100 mm/second to about 300 mm/second, injection pressure from about 50 Bar to about 180 Bar, holding pressure from about 10 Bar to about 200 Bar, back pressure from about 5 Bar to about 25 Bar, and any combination thereof.
19. A packaged silicone hydrogel contact lens product, comprising:
a polymeric contact lens body that is a reaction product of a polymerizable composition, the polymerizable composition comprising
(a) at least one siloxane monomer,
(b) at least one hydrophilic monomer, and
(c) at least one crosslinking agent;
a portion of contact lens packaging solution comprising at least one water-soluble vinyl alcohol copolymer; and
a contact lens package configured to contain a contact lens body in the portion of contact lens packaging solution.