WATER SOLUBLE, RANDOMLY SUBSTITUTED PARTIAL N-, PARTIAL O-ACETYLATED CHITOSAN, PRESERVING COMPOSITIONS CONTAINING CHITOSAN, AND PROCESSES FOR MAKING THEREOF

摘要

The present invention is directed to a pharmaceutical preserving composition comprising: (a) at least one chitosan or chitosan derivative and (b) at least one buffer solution, as well as methods of preserving contact lens solutions and disinfecting contact lens using such composition. The present invention is further directed to a method of preparing O-acetylated chitosan or chitosan derivatives comprising the steps of dissolving the chitosan or chitosan derivative into an aqueous acidic solution and reacting the chitosan or chitosan derivative with an acetylating agent in the presence of a phase transfer reagent.