Formulation and in vitro characterization of cefpodoxime proxetil gastroretentive microballoons

Background and the purpose of the study: The objective of the present work was to improve bioavailability of cepodoxime proxetil through gastroretentive microballoon formulation. Methods: Microballoons of cefpodoxime proxetil were formulated by solvent evaporation and diffusion method employing hydroxypropylmethyl cellulose (HPMC) and ethyl cellulose (EC) polymers and characterized for particle size, surface morphology, incorporation efficiency, floating behavior, in vitro drug release study and differential scanning calorimetry (DSC). Results: The average particle size of formulated microballoons was in the range of 54.23 +/- 2.78-95.66 +/- 2.19 mu m. Incorporation efficiencies of over 83.77 +/- 0.85 % were achieved for the optimized formulations. Most of formulations remained buoyant (having buoyancy percentage maximum of 81.36 +/- 1.96%) for more than 12 hrs indicating good floating behavior of microballoons. Higher values of correlation coefficients were obtained with Higuchi's square root of time kinetic treatment heralding diffusion as predominant mechanism of drug release. Conclusion: Inferences drawn from in vitro studies suggest that microballoons may be potential delivery system for cefpodoxime proxetil with improvement in bioavailability in comparison to conventional dosage forms.