FORMULATION AND EVALUATION OF PREDNISOLONE LOADED MICROSPONGES FOR COLON DRUG DELIVERY: IN- VITRO AND PHARMACOKINETIC STUDY

The purpose of this study was to develop prednisolone-loaded microsponges for colon specific drug delivery. The microsponges formulations were prepared by quasi-emulsion solvent diffusion method employing eudragit RS 100 as a polymer. The compatibility of the drug with formulation components was established by Fourier Transform Infra-Red (FTIR) spectroscopy. Afterwards, microsponge formulations were prepared by gradually increasing the drug: polymer ratio. The surface morphology, particle size, production yield, and drug entrapment efficiency of microsponges were examined. Shape and surface morphology of the microsponges were examined using scanning electron microscopy. Particle size of prepared microsponges was observed in the range of 465 +/- 12.5 to 82.2 +/- 15 mu m. The drug entrapment efficiency of the microsponges was found in the range of 53.38 +/- 0.95 to 91.75 +/- 1.60 %. The in-vitro dissolution studies of microsponges in the media with different pH (1.2, 7.4 and 6.8) showed that drug release in colon could be controlled by Eudragit RS 100. It was observed that the release kinetics on the basis of the highest r(2) values best fitted a zero-order kinetic model. Cumulative release for the microsponges over 8 h ranged from 48 - 87 %. Plasma drug concentration of drug was also studied for optimized formulation and C-max, T-max, and AUC (area under curve) was also observed.