AZO POLYMERIC HYDROGELS FOR COLON TARGETED DRUG-DELIVERY

Azo polymeric hydrogels were developed for colon specific targeting. M ethacryloyloxy azobenzene was synthesized and hydrogels were prepared by copolymerizing with hydroxyethyl methacrylate. These hydrogels were characterized by various spectral techniques such as Fourier transfor m infrared spectroscopy, thermogravimetric analysis and scanning elect ron microscopy. Equilibrium swelling measurements of the hydrogels wer e carried out in distilled water and also in simulated gastric and int estinal fluids. The in vitro release studies of the incorporated 5-flu rouracil were carried out in simulated gastric and intestinal fluids. The in vitro release profiles of the drug were also obtained in the pr esence of azoreductase in the culture of intestinal flora. The release was faster and almost followed a zero order pattern. This can be attr ibuted to the cleavage of the azo crosslinks in the hydrogel by the az oreductase and the release of the entrapped drug at the site of target ing i.e., colon.