Preparation and Evaluation of Sustained Release Colon Targeted Micropellets of Lornoxicam
The aim of the present work was to develop and evaluate sustained release colon targeted micropellets of lornoxicam in order to achieve release of the drug at colon which could result in enhanced local absorption and thereby improved bio-availability. The present worker prepared micropellets of lornoxicam in nine batches using pure drug, DCP, PVPK-30 and different ratios of HPMCK-4M taking into account the direct pelletization technique. Resulted micropellets were fiilled in capsules and coated with eudragit S-100 to achieve colon targeted release. Compatibility studies were by using FTIR and TLC methods. Particle size determination of micronized lornoxicam was performed by SEM which revealed that the mean particle diameter was in the range of 104-263 μm while percentage yield was in the range of 88.4-98.4%.Various pre-formulation physiochemical parameters of formulation blends were evaluated such as bulk density, tapped density, carr’s index, hausner’s ratio and angle of repose and coating durability test for coated capsules (passed). The optimized batch was compared for its release profile in pH 7.4 phosphate buffers and simulated colonic fluid, which were found to be 94.64% and 90.58% respectively. The actual responses were in accordance with the predicted values which showed validity of the model. There were no physical and chemical changes occurred in accelerated stability of tablets during three months study.