Synthesis and characterization of biodegradable chitosan beads as nano-carriers for local delivery of satranidazole

The main aim of this research is to design a new extended release gastroretentive multiparticulate delivery system by incorporation of the hydrogel beads made of chitosan. As the first part of a continued research on conversion of N-sulfonato-N,O-carboxymethylchitosan(NOCCS) to useful biopolymer-based materials, large numbers of carboxylic functional groups were introduced onto NOCCS by grafting with polymethacrylic acid (PMAA). The free radical graft copolymerization was carried out at 70 degrees C, bisacrylamide as a cross-linking agent and persulfate as an initiator. The equilibrium swelling studies were carried out in enzyme-free simulated gastric and intestinal fluids (SGF and SIF, respectively). Also, the satranidazole as a model drug was entrapped in nano-gels and in vitro release profiles were established separately in both enzyme-free SGF and SIF. The drug release was found to be faster in SIF. The drug-release profiles indicate that the drug release depends on their degree of swelling and cross-linking. Crown Copyright (C) 2010 Published by Elsevier Ltd. All rights reserved.