Prednisolone Loaded Tamarind Gum Microspheres for Colonic Delivery

The aim of this work was to formulate a novel multiparticulate system having pH sensitive property and specific enzyme biodegradability for colon specific drug delivery of Prednisolone (PD). Natural polysaccharide, Tamarind gum is used for microsphere preparation and Eudratit S- 100 for coating to provide pH controlled drug release. The formulation aims at minimal degradation and optimum delivery of the drug with relatively higher local concentration, which may provide more effective therapy for inflammatory bowel disease including Crohn disease and ulcerative colitis. Tamarind gum microspheres were prepared by emulsion dehydration technique using polymer in ratio of 1:1 to 1: 9. These microspheres were coated with Eudragit S-100 by oil in oil solvent evaporation method using core: coat ration (5:1). Tamarind gum microspheres and Eudragit coated tamarind gum microspheres were evaluated for surface morphology, particle size and size distribution, percentage drug entrapment, surface accumulation studies, in vitro drug release in simulated gastrointestinal fluids. The effect of various formulation variables were studied the prepared microspheres were spherical in shape in the size range of 64 µm to 113 µm, the encapsulation efficiency was in range of 30-72% depending upon the concentration of gum. The drug release was about 14-20% in first four hours of study gradually rises in 5th hour and 85% drug release occurs in 10-12% hr thus showing desirable drug release in the colonic simulated environment. PD tamarind gum microspheres are thought to have the potential to maintain drug concentration within target ranges for a long time, decreasing the side effects caused by concentration fluctuation, ensuring the efficiency of treatment and improving patient compliance by reducing dosing frequency. The animal study done using acetic acid induced colitis model on rats also suggest the anti inflammatory activity of the formulation.