Nimesulide/cyclodextrin/PEG 6000 ternary complexes: physico-chemical characterization, dissolution studies and bioavailability in rats

Abstract : Purpose : Ternary solid dispersions were prepared in order to estimate the effect of a double hydrophilization by cyclodextrins and PEG 6000 on nimesulide apparent characteristics. Ternary solid dispersions of nimesulide, cyclodextrins and PEG 6000 were characterized using DSC, FT-IR, dissolution studies and evaluating the bioavailability in rats. Methods : Ternary solid dispersions were prepared either using native powders or using a preformed inclusion complex of nimesulide and cyclodextrin. Inclusion complexes and pure drug were used as references. Circulating nimesulide was measured out in rat plasma after orally administration of our different products (ternary solid dispersions, inclusion complexes and pure drug). Results : An improvement of the nimesulide dissolution rate was obtained with inclusion complexes and ternary solid dispersion. In rat plasma, inclusion complexes and ternary solid dispersion improved T max. Conclusions : A second hydrophilization of inclusion complexes by PEG 6000 does not allow to achieve better results concerning nimesulide concentration in rat plasma or in dissolution studies than with inclusion complexes alone.