Hydrogel composition comprising a crosslinked polymer

A method for producing a sterile hydrogel composition, comprising the steps of

• a) providing a thiol-modified hyaluronan,
• wherein the thiol-modified hyaluronan has a degree of modification with thiol groups of more than about 80 μmol per gram polymer, preferably more than about 105 μmol per gram polymer, more preferably more than about 120 μmol per gram polymer, and
• wherein the thiol-modified hyaluronan has a degree of modification with thiol groups of less than about 280 μmol per gram polymer, preferably less than about 240 per gram polymer, more preferably less than 200 μmol per gram polymer, in an aqueous solution,
• b) oxidizing the thiol-modified hyaluronan by exposing the previously obtained aqueous solution to conditions that allow the thiol-modified hyaluronan to form a crosslinked polymer, wherein the aqueous solution becomes a hydrogel, which hydrogel has a residual thiol content of less than 20% in respect to the degree of modification of the thiol-modified hyaluronan,
• optionally c) adding an unmodified polymer selected from the group of biocompatible polysaccharides to the previously obtained hydrogel or to the previously obtained solution,
• optionally d) sieving the previously obtained hydrogel to obtain a hydrogel with a particular particle sizes,
• e) filing the previously obtained hydrogel into a container, in particular a syringe, and exposing the filled container to conditions allowing for sterilization of the hydrogel, and
• f) obtaining a sterile hydrogel composition in a container comprising a crosslinked polymer.