DEVELOPMENT, CHARACTERIZATION AND EVALUATION OF COLON SPECIFIC MICRROSPHERES OF BUDESONIDE

: The objective of the present study was to development, characterization and evaluation of colon specific microspheres of Budesonide. To achieve these objective nine formulations of microspheres were prepared by emulsion solvent evaporation method using Eudragit RS100 and Kollicoat MAE 100 P polymer. Prepared microspheres were evaluated for Particle size analysis, Surface morphology, Differential scanning calorimetric analysis, Fourier transform infrared spectroscopy analysis, X-ray diffraction studies, Drug encapsulation efficiency, In-vitro drug release study and Stability study. The microspheres formed have smooth surface and spherical shape as observed in scanning electron microscopy. The drug entrapment efficiency (DEE) of the formulation is in the range of 82.44% to 90.69%. Particle size increases with increasing concentration of polymer, particle size ranging from 4. 892µm to 5. 16µm. The Drug-polymer compatibility was studied by using FTIR spectroscopy. The study revealed that there is no interaction between the selected drug and polymers. Differential scanning colorimetry analysis of prepared microspheres indicates that there is no interaction between the drug and polymers. X-ray diffractograms of prepared microspheres indicates that the drug is amorphously dispersed in the formulation and enhances the dissolution of the drug. The drug release study was done in simulated gastrointestinal fluids for 2 hrs in gastric fluid (pH 1.2), for 3 hrs in intestinal fluids (pH 6.8) and up to 24hrs in Colonic fluids (pH 7.4) and has shown that the drug was protected from being released in the physiological environment of the stomach and small intestine and efficiency released in Phosphate buffer pH 7.4 (colonic pH). The results showed maximum amount of drug accumulation in colonic pH. Drug release mechanism followed non-Fickian transport. The formulations were found to be stable in short term stability studies. analysis:-The DSC analysis is the most widely used to characterize the physical state of drug in the formulations. The DSC thermograms of Budesonide exhibited a single sharp endothermic peak at 260. 32ºC due to melting transition point of drug. The drug free microspheres have exhibited endothermic peak at 72ºC and 189ºC, and drug containing formulation (BDS9) exhibited peak at 64. 26ºC and 189. 93ºC in the DSC thermogram. There is no melting peak of drug at 260ºC appeared in thermogram indicating the complete dispersion of drug in the carrier polymer due to phase transition. This indicates that there is no interaction between the drug and polymers. The results are given in Fig 03. studies:-The X-ray diffractograms of pure drug Budesonide, drug free microspheres (dummy) and drug loaded microspheres (BDS9) and Budesonide shown 2θ characteristic intense peak between 6. 2º, 12. 2º, 15. 6º, 16. 1º and 24º representing higher crystalline nature. Some of the crystalline peaks of the drug were still detectable in the formulation but with reduce the intensity and less number in the defractograms. This indicates that the drug is amorphously dispersed in the formulation and enhances the dissolution of the drug Fig 05.