Physical characterization of a chitosan-based hydrogel delivery system

Hydrogel formation from a mixture of biocompatible chitosan, P-glycerol phosphate, and hydroxyethyl cellulose was studied. The rheological properties of the formed hydrogels were examined using a Bohlin VOR rheometer. The effect of hydrogel composition and temperature on both the gelation rate and the elastic strength of hydrogels was investigated, from which possible hydrogel formation mechanisms were inferred. The formed hydrogels as potential vehicles for delivering pilocarpine were examined. The advantages and disadvantages of chitosan/hydroxyethyl cellulose hydrogel as a delivery system are discussed. (C) 2002 Wiley-Liss, Inc. and the American Pharmaceutical Association.