Contact lenses made with HEMA-compatible polysiloxane macromers
View Patent ↗Optically clear silicone hydrogel contact lenses are described that comprise a polymeric lens body that is the reaction product of a polymerizable composition comprising at least 25 wt. % of at least one hydroxyalkyl methacrylate; and at least 20 wt. % of at least one HEMA-compatible bifunctional polysiloxane comprising at least 6 siloxane groups and having an HLB value of at least 5 and/or a hydroxyl group content of at least 1 wt. %.
1. An optically clear silicone hydrogel contact lens comprising:
a polymeric lens body that is the reaction product of a polymerizable composition comprising:
a) at least 25 wt. % of at least one hydroxyalkyl methacrylate; and
b) at least 20 wt. % of at least one HEMA-compatible bifunctional polysiloxane comprising at least 6 siloxane groups,
wherein the HEMA-compatible bifunctional polysiloxane has an HLB value of at least 7,
wherein the wt. % of the hydroxyalkyl methacrylate and the HEMA-compatible bifunctional polysiloxane is based on the total weight of polymerizable monomers in the composition.
2. The contact lens of claim 1 , wherein the HEMA-compatible bifunctional polysiloxane has the structure of Formula 4:
wherein R 1 and R 2 are independently selected from either hydrogen or a methyl group, k is an integer of 0 or 1, m is an integer of 0 to 160, n is an integer of 1 to 75, p is an integer of at least 6, and q is an integer of 0 to 20.
3. The contact lens of claim 1 , wherein the HEMA-compatible bifunctional polysiloxane has a hydroxyl group content of at least 1 wt. % based on the average molecular weight of the polysiloxane.
4. The contact lens of claim 1 , wherein the polymerizable composition further comprises:
c) 1 to 65 wt. % diluent, wherein the wt. % of the diluent is based on the total weight of the polymerizable composition, and wherein the diluent comprises water, a low molecular weight polyethylene glycol (PEG), or a combination thereof.
5. The contact lens of claim 4 , wherein the HEMA-compatible bifunctional polysiloxane requires water addition for optical clarity.
6. The contact lens of claim 1 , wherein the polymerizable composition comprises from 0.1 wt. % up to about 5 wt. % methacrylic acid or acrylic acid.
7. The contact lens of claim 1 , wherein the polymerizable composition comprises at least 35 wt. % of the hydroxyalkyl methacrylate.
8. The contact lens of claim 1 , wherein the hydroxyalkyl methacrylate is 2-hydroxyethyl methacrylate (HEMA).
9. The contact lens of claim 1 , having a Dk of at least 35.
10. The contact lens of claim 1 , wherein the polymerizable composition comprises a monomer selected from methacrylic acid, acrylic acid, glycerol methacrylate, and combinations thereof.
11. The contact lens of claim 10 , wherein the polymerizable composition optionally comprises a crosslinking agent, a polymerizable dye, or both a crosslinking agent and a polymerizable dye, and no other polymerizable components.
12. A method of manufacturing the optically clear contact lens of claim 1 , comprising:
a) polymerizing the polymerizable composition to form the polymeric lens body; and
b) hydrating the polymeric lens body,
wherein the polymerizable composition is either diluent-free or comprises about 1 to 65 wt. % of a diluent consisting essentially of water or a low molecular weight PEG, or a combination thereof, wherein the wt. % of the diluent is based on the total weight of the polymerizable composition.
13. The method of claim 12 , wherein the polymerizable composition is cured in a mold to form the polymeric lens body, and wherein the polymeric lens body is dry-delensed from the mold prior to hydrating the polymeric lens body.