Polymer hydrogels adapted for use as soft contact lenses, and method of preparing same
AssigneeAlcon Laboratories, Inc.
InventorsDoris Schafer, Rolf Schafer
Life of this patent
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Abstract
The improved polymeric hydrogel suitable for use in forming soft contact lenses is described. The hydrogel is improved by means of its resistance to the formation of calcium, lipid and protein deposits thereon. This resistance is achieved by means of covalent modification of the hydrogel with a surfactant.
Claims21
An improved polymeric hydrogel, comprising a polymeric hydrogel that has been modified by treating unmodified polymeric hydrogel containing polar functional groups with a surfactant selected from:
- carboxylated surfactants of formula (I):
- R--O(CH.sub.2 --CH.sub.2 --O).sub.x --CH.sub.2 --COOH and formula (II):
- R--NH(CH.sub.2 --CH.sub.2 --CH.sub.2 --NH).sub.x --CH.sub.2 --CH.sub.2 --CH.sub.2 --COOH;
- nonionic surfactants of formula (III):
- R--O(CH.sub.2 --CH.sub.2 --O).sub.x --CH.sub.2 --CH.sub.2 --OH;
- polycationic surfactants of formula (IV):
- R--NH(CH.sub.2 --CH.sub.2 --CH.sub.2 --NH).sub.x --CH.sub.2 --CH.sub.2 --CH.sub.2 --NH.sub.2 ;
- wherein R is a C.sub.8 to C.sub.18 hydrocarbon chain and x is from 1 to 10 in the surfactants containing nitrogen and from 4 to 16 in the surfactants containing oxygen, said treatment being carried out in a modification regulating medium selected from the group consisting of urea, organic solvents and saline solutions, said modification regulating medium containing a carbodiimide coupling agent.
A modified polymeric hydrogel, comprising a polymeric hydrogel containing polar functional groups selected from hydroxyl and carboxyl, at least some of said polar functional groups being covalently bonded to a surfactant selected from:
- carboxylated surfactants of formula (I):
- R--O(CH.sub.2 --CH.sub.2 --O).sub.x --CH.sub.2 --COOH and formula (II):
- R--NH(CH.sub.2 --CH.sub.2 --CH.sub.2 --NH).sub.x --CH.sub.2 --CH.sub.2 --CH.sub.2 --COOH;
- nonionic surfactants of formula (III):
- R--O(CH.sub.2 --CH.sub.2 --O).sub.x --CH.sub.2 --CH.sub.2 --OH;
- and polycationic surfactants of formula (IV):
- R--NH(CH.sub.2 --CH.sub.2 --CH.sub.2 --NH).sub.x --CH.sub.2 --CH.sub.2 --CH.sub.2 --NH.sub.2 ;
- wherein R is a C.sub.8 to C.sub.18 hydrocarbon chain, and x is from 1 to 10 in the surfactants containing nitrogen and from 4 to 16 in the surfactants containing oxygen.
A method of modifying polymeric hydrogels to improve the resistance of the hydrogels to the formation of calcium, lipid and protein deposits thereon, comprising:
- immersing the polymeric hydrogel in a modification regulating medium containing a coupling agent and a surfactant selected from:
- carboxylated surfactants of formula (I):
- R--O(CH.sub.2 --CH.sub.2 --O).sub.x --CH.sub.2 --COOH and formula (II):
- R--NH(CH.sub.2 --CH.sub.2 --CH.sub.2 --NH).sub.x --CH.sub.2 --CH.sub.2 --CH.sub.2 --COOH;
- nonionic surfactants of formula (III):
- R--O(CH.sub.2 --CH.sub.2 --O).sub.x --CH.sub.2 --CH.sub.2 --OH;
- and polycationic surfactants of formula (IV):
- R--NH(CH.sub.2 --CH.sub.2 --CH.sub.2 --NH).sub.x --CH.sub.2 --CH.sub.2 --CH.sub.2 --NH.sub.2 ;
- wherein R is a C.sub.8 to C.sub.18 hydrocarbon chain and x is from 1 to 10 in the surfactants containing nitrogen and from 4 to 16 in the surfactants containing oxygen;
- soaking the polymeric hydrogel in the modification regulating medium for from about 5 minutes to 2 hours at a temperature of from about 20.degree. to 100.degree. C.;
- and
- removing the polymeric hydrogel from the modification regulating medium.
Dependencies are inferred from the claim text.