Development and Characterization of Controlled Release Ketoprofen Microspheres

Microspheres ketoprofen (KP) were prepared by o/w emulsion solvent evaporation technique using EudragitRS100 as a polymeric material. The effect of process variables such as drug: polymer ratio, stirring rate, emulsifier concentration, internal organic solvent and dispersing medium volumes were examined. The prepared formulations were characterized for particle size distribution, percent yield, entrapment efficiency, in vitro release and in vivo studies behavior. The study revealed that the mean particle size ranged from 293.06 to 438.63 μm, the KP loading efficiency varied from 60.19-87.63% of the theoretical amount incorporated, all microspheres patches exhibited a prolonged release for almost 24 hrs and the release pattern was diffusion model. The pharmacokinetic parameters, Cmax, Tmax, AUC0-24 and AUC0-∞ were calculated from the plasma drug concentration-time data. Plasma KP concentrations and pharmacokinetics parameters were statistically analyzed. The test formulation exhibited controlled and prolonged absorption (Tmax) of 6.79 ± 0.0.39 vs. 2.03 ± 0.08 and 3.32 ± 0.24 hs; Cmax of 14.42 ± 0.50 vs. 18.78 ± 0.95 and 16.58 ± 1.02 μg/ml) when compared to the plain drug and marketed product, respectively. In-vivo studies revealed that the relative bioavailability of the KP increased by more than 1.3 times by formulating it into microspheres compared to plain drug.