Development and evaluation of eudragit based microparticles of dexibuprofen for site specific drug release

The main purpose of work was to formulate dexibuprofen loaded eudragit L-100 micro particles to acquire site specific delivery of dexibuprofen. Micro particles were formulated by an emulsion solvent evaporation method. Four formulations F1, F2, F3 and F4 having drug to polymer ratio 1:1, 1:2, 1:3 and 1:4, respectively were prepared and characterized. The rheological properties manifested that micro particles were worthy for further pharmaceutical exploitation. No notable drug polymer interaction was perceived in FT-IR spectroscopy. SEM micrographs showed rough surface of micro particles. The resulting micro particles had high entrapment efficiency greater than 70%. The in vitro dexibuprofen release at pH 1.2 exhibited poor drug release with less than 21% while at pH 6.8, 60% of the dexibuprofen was released up till 8th hour. The dexibuprofen release was modified by altering polymer concentration in the formulation. The subsequent micro particles were found to be best fit with zero-order release model. Micro particles were efficiently formulated with a focus to release the drug majorly in small intestine. With increase of polymer concentration enhanced entrapment efficiency and decelerated dexibuprofen release from the micro particles has been achieved. In vitro dexibuprofen studies verified the gastro-resistant property of micro particles thus qualify site specific release in gastrointestinal tract.