Piperine containing floating microspheres: an approach for drug targeting to the upper gastrointestinal tract

The purpose of this investigation was to prepare and characterize acyclovir loaded floating microspheres by emulsification solvent evaporation method. Piperine was added to investigate its effect on acyclovir bioavailability. The microspheres were characterized for size, shape, entrapment efficiency, in vitro drug release, and in vivo pharmacokinetic parameters. The morphological characterization of microspheres was done using a scanning electron microscope. The microspheres were spherical and had particle size in the range of 400 to 525 μm. The percent drug entrapment efficiency varied between 56.12 ± 1.32 % to 87.32 ± 5.28 %. The drug release was decreased at higher polymer concentrations. Nearly two times higher AUC0-24 value of acyclovir-loaded piperine containing microspheres (15614.13 ± 6953.13 ng h ml(-1)) was observed as compared to the drug solution (7552.33 ± 3219.09 ng h ml(-1)). Under the accelerated storage conditions, the best selected formulation was found to be stable for 90 days. The preliminary results of this study suggest that the developed microspheres containing acyclovir could enhance drug entrapment efficiency, reduce initial burst release, and prolong the drug release with enhanced bioavailability.