Preparation of rosiglitazone maleate sustained-release floating microspheres for improved bioavailability

The object of this study was to prepare rosiglitazone maleate (RM) sustained-release floating microspheres and investigate their pharmacokinetics. RM microspheres were prepared with ethyl cellulose (EC) and octadecyl alcohol as the carrier materials by an emulsion-solvent diffusion method, and the properties of morphology in vitro floating capability, drug loading (DL), entrapment efficiency (EE), in vitro release and in vivo pharmacokinetics were investigated. The prepared microspheres had a completely spherical shape. The percentage of microspheres floating after 12 h was (91.45 +/- 1.62)%, and the DL and EE were (9.31 +/- 0.31)% and (89.55 +/- 1.65)% respectively. Pharmacokinetic studies demonstrated that the RM floating microspheres were superior to commercial tablets in terms of the decrease in peak plasma concentration and maintenance of RM concentration in plasma. The area under the curve of plasma concentration-time (AUC) of the floating microspheres was equivalent to that of reference tablets. The results showed that floating microspheres are a feasible approach for the sustained-release preparation of drugs which have limited absorption sites in the upper small intestine.