Effect of Ethyl Cellulose Content on Release Profile and Pharmacodynamics of Fenoprofen Microparticles

Introduction: Fenoprofen calcium (FC) is a non-steroidal anti-inflammatory drug and due to its short half-life, high absorption, extensive metabolism and adverse effect, sustained release formulation of FC is desired. Objective: this study was to develop sustained release microcapsules of FC to obtain better drug delivery. Material and Methods: Different formulae of FC microcapsules were prepared by o/w emulsion solvent evaporation method using Ethyl cellulose (EC) in three different ratios. The processed microcapsules were evaluated in-vitro for production yield, entrapment efficiency, micromeritic properties and thermal characteristics and in-vivo for its pharmacodynamics. Results: In-vitro release studies of formulae H1 and H3 showed regression coefficient (r) value in the Higuchi diffusion model of 0.967 and 0.946 respectively, suggesting diffusion mechanism release from these forms. While marketed capsules and H2 microcapsules showed regression coefficient value in the zero-order model (0.985 and 0.985 respectively), suggesting non-linear release. In-vivo, the carrageenan-induced hind paw edema was induced in rats; the area under the inhibition of inflammation percentage–time curve (AUC0-24) showed that formula H3 possesses the highest therapeutic efficiency comparing with marketed capsules followed by formula H1 and finally H2. Moreover, in hot plate test in mice, there were highly significant increases in the mean reaction time in groups H2 and H3 over the marketed capsule at 12h interval (p<0.001). Conclusion: FC loaded EC microcapsule H3 produced a sustained and effective drug release over a prolonged timeframe that led to greater therapeutic efficacy.