Silicone hydrogel contact lenses having non-uniform morphology

Abstract

The invention relates to a polysiloxane hydrogel contact lens with a non-uniform morphology. The contact lens can be made from a reactive mixture comprising: a polysiloxane component; a hydrophilic component; a non-reactive polymeric internal wetting agent; and a polymerization initiator. The contact lens has an oxygen permeability of at least about 60 barrers, and wherein the molar ratio of the polymeric non-reactive internal wetting agent to the polysiloxane in the contact lens is greater in the surface of the contact lens than in its bulk without surface treatment.

Claims

1. A polysiloxane hydrogel contact lens, which is a reaction product of a reactive mixture comprising: a polysiloxane component; a hydrophilic component; a non-reactive polymeric internal wetting agent; and a polymerization initiator, the contact lens having an oxygen permeability of at least about 60 barrers, and wherein the molar ratio of the polymeric non-reactive internal wetting agent to the polysiloxane in the contact lens is greater in the surface of the contact lens than in its bulk without surface treatment; wherein... The reactive mixture is cured under thermosetting conditions; and wherein the molar ratio in the surface of the contact lens is measured by infrared spectroscopy in attenuated total reflectance (ATR) mode, while the molar ratio in the body of the contact lens is measured by infrared spectroscopy in transmittance mode.

2. The polysiloxane hydrogel contact lens as claimed in claim 1, wherein the molar ratio of the polymeric non-reactive internal wetting agent to polysiloxane is at least 1.5 times greater in the surface of the contact lens than in its body.

3. The polysiloxane hydrogel contact lens as described in any one of claims 1 to 2, wherein the molar ratio of the polymeric non-reactive internal wetting agent to the polysiloxane is at least 2.3 times greater in the surface of the contact lens than in its body.

4. The polysiloxane hydrogel contact lens as described in any one of claims 1 to 2, wherein the non-reactive polymeric internal wetting agent is polyamide.

5. The polysiloxane hydrogel contact lens as described in any one of claims 1 to 2, wherein the non-reactive polymeric internal wetting agent is selected from polyvinylpyrrolidone (PVP), polyvinylmethyl acetamide (PVMA), polydimethylacrylamide (PDMA), polyvinylacetamide (PNVA), poly(hydroxyethyl(meth)acrylamide), polyacrylamide, copolymers thereof, and mixtures thereof.

6. The polysiloxane hydrogel contact lens as described in claim 5, wherein the non-reactive polymeric internal wetting agent is polyvinylpyrrolidone (PVP).

7. A polysiloxane hydrogel contact lens as claimed in any one of claims 1 to 2, wherein in a contact lens containing a reactive mixture of the non-reactive polymeric internal wetting agent at a weight percentage of less than 2.0%, the contact lens comprises an advancing contact angle of 75° or less.

8. The polysiloxane hydrogel contact lens as described in claim 7, wherein the forward contact angle is 50° or less.

9. The polysiloxane hydrogel contact lens as described in any one of claims 1 to 2, comprising up to about 95 percent by weight of a polysiloxane-containing component.

10. The polysiloxane hydrogel contact lens as described in any one of claims 1 to 2, comprising about 1 to about 80 percent by weight of a hydrophilic component.

11. The polysiloxane hydrogel contact lens as described in any one of claims 1 to 2, comprising about 0.5 to about 35% by weight of a non-reactive polymeric internal wetting agent.

12. The polysiloxane hydrogel contact lens as claimed in any one of claims 1 to 2, wherein the non-reactive polymeric internal wetting agent has a weight average molecular weight of about 150,000 to about 2,000,000 Daltons.

13. The polysiloxane hydrogel contact lens as claimed in any one of claims 1 to 2, wherein the polysiloxane component is a mixture of 2-hydroxy-3-[3-methyl-3,3-di(trimethylsiloxy)silylpropoxy]-propyl methacrylate (SiMAA) and monomethacryloxypropyl-terminated mono-n-butyl-terminated polydimethylsiloxane (mPDMS).

14. The polysiloxane hydrogel contact lens as claimed in any one of claims 1 to 2, wherein the hydrophilic component is a mixture of N,N-dimethylacrylamide (DMA) and 2-hydroxyethyl methacrylate (HEMA).

15. The polysiloxane hydrogel contact lens as described in any one of claims 1 to 2, wherein the polymerization initiator is 1,1'-azobisisobutyronitrile (AIBN).

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