Patent ID: 8663686

Claim:
A composition comprising a crosslinked interpolymer of chitosan and polyethylene glycol, wherein chitosan is covalently coupled to polyethylene glycol in the interpolymer through a —NH—CH 2 — linkage, the —NH— of the —NH—CH 2 — linkage derived from chitosan and the —CH 2 — of the —NH—CH 2 — linkage derived from polyethylene glycol, wherein the chitosan has an average molecular weight from 190,000 to about 2,000,000 Daltons, wherein the polyethene glycol is present in the interpolymer in an amount of from 45% by weight to 55% by eight based on the total weight of the interpolymer, and wherein the composition is a liquid below 25° C. and a gel above 35° C.