Formulation and Evaluation of Satranidazole Microspheres For Colon Targeted Drug Delivery

The purpose of this research was to develop and evaluate Eudragit based microspheres exploiting pH sensitivity property and specific biodegradability for colon targeted delivery of Satranidazole. Eudragit based microspheres were prepared by oil-in-oil solvent evaporation method using different drug- polymer ratios (1:1 to 1:5), stirring speeds (1200-1400 rpm) and emulsifier concentrations (0.5%-1.0 % wt/vol). Differential scanning calorimetry, study of the physical mixtures of drug and polymer revealed no drug-polymer interaction. All formulations were evaluated for particle size and shape, swellability and percentage drug entrapment. The yield of preparation and the encapsulation efficiencies were high for all Eudragit microspheres. The in vitro drug release study of optimized formulation was also performed in simulated gastrointestinal fluids (SGF). The release profile of satranidazole from Eudragit microspheres was pH dependent. In acidic medium, the release rate was much slower; however, the drug was released quickly at pH 7.4. It is concluded from the present investigation that Eudragit microspheres are promising controlled release carriers for colon-targeted delivery of satranidazole