Formulation, evaluation and optimization of microspheres of anti-inflammatory drug diacerein using polymer carbopol for the treatment of osteoarthritis

Abstract

The objectives of the present study were to select a formulation that has an ideal in vitro dissolution profile and to compare the sustaining/ controlling efficacy of the selected formulation with that of the commercial conventional tablet in order to establish a good degree of in vitro–in vivo correlation. The microspheres were subjected to characterization for particle size, encapsulation efficiency, loose crystal study, stability study, in vitro release rate profile, release kinetics and in vivo study in New Zealand white rabbit species. A single-dose oral bioavailability study revealed significant differences in Cmax, Tmax, T, Ka, Ke, MRT, MDT and AUC between the conventional tablet and optimized microsphere dosage forms. Furthermore, linear relationship obtained between the percentages dissolved and absorbed suggests a means to predict in vivo absorption by measuring in vitro dissolution. Thus F5 formulation showed the best in vivo performance exhibiting deliberate release.