Method for sterilization of hydrogel contact lenses

Abstract

The present invention provides an aqueous solution for sterilizing and storing ophthalmic devices, preferably a contact lens, made of a hydrogel material, preferably a poly(oxyalkylene)-containing hydrogel material. The solution comprises one or more organic buffer agents, such as a Good buffer or a bis-aminopolyols; an organic tonicity-adjusting agent with multiple hydroxyl groups in an amount sufficient to provide an osmolarity of from about 200 to about 450 mosm / l, wherein the aqueous solution has a pH of from about 5.5 to about 8.5, provided that the aqueous solution include phosphate buffer at a concentration of about 15 mM or less and about 5000 ppm sodium chloride. The present invention also provides a method for sterilizing and storing an ophthalmic device using an aqueous solution of the invention.

Description

[0001]This application claims the benefit under 35 U.S.C.§ 119 (e) of U.S. provisional application Ser. No. 60 / 774,984 filed Feb. 17, 2006[0002]The present invention relates to a method for sterilization of ophthalmic devices composed of a hydrogel material, especially a poly(oxyalkylene)-containing polymeric material. More specifically, the present invention relates to a method for sterilizing an ophthalmic device made of a poly(oxyalkylene)-containing polymeric material, wherein the method is characterized by having a reduced autoclave-induced haziness of the ophthalmic device. In addition, the present invention relates to a packaging solution for sterilizing and storing ophthalmic devices made of a hydrogel material, preferably comprising a poly(oxyalkylene)-containing, wherein the solution is capable of reducing autoclave-induced haziness of the poly(oxyalkylene)-containing polymeric material.BACKGROUND OF THE INVENTION[0003]Because of the biocompatibility of poly(alkyleneglycol...

AI Technical Summary

Benefits of technology

[0006]In one aspect, the present invention provides an aqueous solution for sterilizing and storing an ophthalmic device, wherein the ophthalmic device is made of a poly(oxyalkylene)-containing polymeric material. The aqueous solution of the invention comprises: an α-oxo-multi-acid or salt thereof in an amount sufficient to have a reduced susceptibility to oxidation degradation of the poly(oxyalkylene)-containing polymeric material; one or more buffer agents selected from group consisting of TRIS (tris(hydroxymethyl)aminomethane), 2-bis(2-hydroxyethyl)amino-2-(hydroxymethyl)-1,3-propanediol, bis-aminopolyols, triethanolamine, ACES (N-(2-hydroxyethyl)-2-aminoethanesulfonic acid), BES (N,N-Bis(2-hydroxyethyl)-2-aminoethanesulfonic acid), HEPES (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid), MES (2-(N-morpholino)ethanesulfonic acid), MOPS 3-[N-morpholino]-propanesulfonic acid, PIPES (piperazine-N,N′-bis(2-ethanesulfonic acid), TES (N-[Tris(hydroxymethyl)methyl]-2-aminoethanesulfonic acid), and salts thereof; an organic tonicity-adjusting agent in an amount sufficient to provide an osmolarity of from about 200 to about 450 milli-osmole in 1000 ml (unit: mOsm/L), wherein the organic tonicity-adjusting agent is selected from the group consisting of glycerol, sorbitol, xylitol, mannitol, propylene glycol, polyethylene glycol (PEG) with a molecular weight of about 400 Da or less, and mixtures thereof, wherein the aqueous solution has a pH of from about 5.5 to about 8.5, provided that the aqueous solution include phosphate buffer at a concentration of about 15 mM or less and about 5000 ppm or less sodium chloride.

[0007]In another aspect, the present invention provides a method for sterilizing and storing ophthalmic devices, comprising the steps of: placing an ophthalmic device in an aqueous solution in a container, wherein the ophthalmic device is made of a poly(oxyalkylene)-containing polymeric material, wherein the aqueous solution comprises: an α-oxo-multi-acid or salt thereof in an amount sufficient to have a reduced susceptibility to oxidation degradation of the poly(oxyalkylene)-containing polymeric material; one or more buffer agents selected from group consisting of TRIS (tris(hydroxymethyl)aminomethane), bis-aminopolyols, triethanolamine, ACES (N-(2-hydroxyethyl)-2-aminoethanesulfonic acid), BES (N,N-Bis(2-hydroxyethyl)-2-aminoethanesulfonic acid), HEPES (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid), MES (2-(N-morpholino)ethanesulfonic acid), MOPS 3-[N-morpholino]-propanesulfonic acid, PIPES (piperazine-N,N′-bis(2-ethanesulfonic acid), TES (N-[Tris(hydroxymethyl)methyl]-2-aminoethanesulfonic acid), and salts thereof; an organic tonicity-adjusting agent in an amount sufficient to provide an osmolarity of from about 200 to about 450 milli-osmole in 1000 ml (unit: mosm/l), wherein the organic tonicity-adjusting agent is selected from the group consisting of glycerol, sorbitol, xylitol, mannitol, propylene glycol, polyethylene glycol (PEG) with a molecular weight of about 400 Da or less, and mixtures thereof, wherein the aqueous solution has a pH of from about 5.5 to about 8.5, provided that the aqueous solution include phosphate buffer at a concentration of about 15 mM or less and about 5000 ppm sodium chloride; sealing the container; and autoclaving the sealed container with the ophthalmic device.

[0008]In a further aspect, the invention provides an ophthalmic product, compris

Problems solved by technology

However, poly(oxyalkylene)-containing polymers may be susceptible to oxidative degradation and high-temperature-induced or autoclave-induced haziness.

Oxidative degradation may cause changes in the properties of an article made from the poly(oxyalkylene)-containing polymers.

Autoclave-induced haziness may adversely affect the optical properties of an ophthalmic device, such as, a contact lens or an intraocular lens made of a poly(oxyalkylene)-containing material.

Those susceptibilities may limit the applications of poly(oxyalkylene)-containing polymers, in particular, in making ophthalmic devices.

But, a poly(oxyalkylene)-containing material still may not be suitable for making ophthalmic devices, because ophthalmic devices must be sterilized, typically by autoclave.

Autoclave-induced haziness may affect adversely the optical properties of the ophthalmic devices and thereby their primary function in correcting vision deficiencies.

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