In vitro/in vivo evaluation of procera gum-ethylcellulose microspheres for colonic delivery of budesonide.

The objective of the present research was to a develop colonic delivery system for budesonide based on polymer blends of natural polysaccharides from Albizia procera and the GI-insoluble polymer ethylcellulose. An emulsion solvent evaporation method was used for the preparation of the microspheres. In vitro drug release was studied in a medium simulating gastrointestinal fluid and the mechanism of drug release was determined using the Korsemeyer-Peppas equation. In vivo performance of the microsphere was evaluated in acetic acid induced colitis in rats. Drug release studies showed that the microspheres with a procera gumethylcellulose coating were able to resist premature drug release in the upper GI tract and yet were susceptible to enzyme effects in the colon. Treatment of rats with a budesonide test formulation for five days significantly attenuated the extent and severity of the cell damage and could thus be a promising system for the treatment of ulcerative colitis.