PROCESS FOR MAKING CATIONIC HYDROPHILIC SILOXANYL MONOMERS

Abstract

The present invention relates to polymeric compositions useful in the manufacture of biocompatible medical devices. More particularly, the present invention relates to certain cationic monomers capable of polymerization to form polymeric compositions having desirable physical characteristics useful in the manufacture of ophthalmic devices. Such properties include the ability to extract the polymerized medical devices with water. This avoids the use of organic solvents as is typical in the art. The polymeric compositions comprise polymerized cationic hydrophilic siloxanyl monomers prepared by the process disclosed herein.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is the NMR Spectra of a monomer prepared according to Example 1.

Claims

1. A method of preparing a water extractable medical device forming monomer, the method comprising: providing a hydride containing siloxane compound,dissolving the hydride containing siloxane compound in a solvent or combination of solvents;treating the dissolved hydride containing siloxane compound with an allylic halide and a standard hydrosilation catalyst to form a first reaction mixture;heating the first reaction mixture under a nitrogen atmosphere for a sufficient time to result in the quantitative loss of reactants as determined by appropriate analytical technique thus providing a monomer mixture;cooling the monomer mixture;concentrating the cooled mixture;dissolving the cooled mixture in a solvent appropriate for nucleophilic substitution;treating the cooled mixture containing the solvent appropriate for nucleophilic substitution with a tertiary amino-vinyl compound to form a second reaction mixture;heating the second reaction mixture at a temperature sufficient to promote reaction without causing gelation;removing any remaining solvent to provide a product containing material; and,purifying the product containing material to yield a water extractable medical device forming monomer.

2. A monomer prepared by the process of claim 1.

3. The monomer of claim 2 having at least one of the following properties as measured by the methods described in Example 2: a water content from 0 wt % to about 80 wt %;an oxygen permeability (Dk) from about 10 to about 200, ora modulus from about 20 g/mm2 to about 2000 g/mm2.

4. A monomer prepared according to the method of claim 1 having an NMR spectra prepared according to the method described in Example 2 that is equivalent to FIG. 1 within generally accepted standards of scientific error.