Patent ID: 8877243

Claim:
A process for producing a cross-linked polysaccharide gel sufficiently cross-linked to resist degradation comprising: (a) contacting hyaluronic acid and at least one additional polysaccharide, mixed in an alkaline medium with a cross-linking agent consisting essentially of a bifunctional epoxide or a polyfunctional epoxide to provide an essentially cross-linked polysaccharide, wherein the cross-linking agent is substantially linked to the polysaccharide by ether bonds; (b) drying the cross-linked polysaccharide under vacuum without substantially removing epoxide from the alkaline medium to form a cross-linked polysaccharide matrix; and (c) neutralizing the cross-linked polysaccharide matrix with an acidic medium to form a cross-linked polysaccharide gel, wherein the cross-linked polysaccharide gel is sufficiently cross-linked by the cross-linking agent to resist degradation and wherein the alkaline medium of (a) above has a pH greater than 9.