Synthesis and evaluation of sucrose-containing polymeric hydrogels for oral drug delivery

Biodegradable and biocompatible copolymeric hydrogels based on sucrose acrylate, N-vinyl-2-pyrrolidinone, and acrylic acid were designed and synthesized. Because of the growing importance of sugar-based hydrogels as drug delivery systems, these new pH-responsive sucrose-containing copolymeric hydrogels were investigated for oral drug delivery. The sucrose acrylate monomer was synthesized and characterized. The copolymeric hydrogel was synthesized by free-radical polymerization. Azobisisobutyronitrile (AIBN) was the free-radical initiator employed and bismethyleneacrylamide (BIS) was the crosslinking agent used for hydrogel preparations. Homopolymeric vinyl pyrrolidone hydrogels were also prepared by the same technique. The hydrogels were characterized by differential scanning calorimetry, thermogravimetric analysis, and scanning electron microscopy. Equilibrium swelling studies were carried out in enzyme-free simulated gastric and intestinal fluids (SGF and SIF, respectively). These results indicate the pH-responsive nature of the hydrogels. The gels swelled more in SIF than in SGF. A model drug, propranolol hydrochloride (PPH), was entrapped in these gels and the in vitro release profiles were established separately in both enzyme-free SGF and enzyme-free SIF. The drug release was found to be faster in SIF. About 93 and 99% of the entrapped drug was released over a period of 24 h in SGF and SIF, respectively. (C) 2002 Wiley Periodicals, Inc.