METHOD FOR MAKING SILICONE HYDROGEL CONTACT LENSES

摘要

The invention provides a method for washing, with a water-based system, reusable molds for making silicone hydrogel contact lenses. The water-based washing system comprises a solvo-surfactant which is an alkyl (propylene glycol)n ether wherein alkyl is a linear alkyl group having 2 to 5 carbon atoms and n is the integer 1, 2 or 3. The water-based system of the invention can effectively wash away silicone-containing components and other components of a lens formulation left behind on the molding surfaces of a reusable mold, after removing a silicone hydrogel contact lens cast molded in the reusable mold.

主权项

1. A method for producing silicone hydrogel contact lenses, comprising the steps of:
(1) providing a reusable mold for making soft contact lenses, wherein the mold has a first mold half with a first molding surface defining the anterior surface of a contact lens and a second mold half with a second molding surface defining the posterior surface of the contact lens, wherein said first and second mold halves are configured to receive each other such that a cavity is formed between said first and second molding surfaces; (2) introduce a fluid polymerizable composition into the cavity, wherein the fluid polymerizable composition comprises at least one silicone-containing lens-forming material selected from the group consisting of a siloxane-containing vinylic monomer, a polysiloxane-containing vinylic monomer, a polysiloxane-containing macromer, a polysiloxane-containing crosslinker, an actinically-crosslinkable silicone-containing prepolymer, and a mixture thereof; (3) irradiating, under a spatial limitation of actinic radiation, the fluid composition in the mold for a time period of about 200 seconds or less, so as to form a silicone hydrogel contact lens, wherein the formed silicone hydrogel contact lens comprises an anterior surface defined by the first molding surface, an opposite posterior surface defined by the second molding surface, and a lens edge defined by the spatial limitation of actinic radiation; (4) opening the mold and removing the formed silicone hydrogel contact lens from the mold; (5) removing the silicone-containing lens forming material and other components of the fluid composition left behind on the first and second molding surfaces of the mold by washing the first and second molding surfaces of the reusable mold with a water-based solution containing from about 0.01% to about 10% by weight of a solvo-surfactant, wherein the solvo-surfactant is an alkyl (propylene glycol)n ether wherein alkyl is a linear alkyl group having 2 to 5 carbon atoms and n is the integer 1, 2 or 3; and (6) repeating the steps (2) to (5).