Der Pharmacia Lettre
Abstract
Author(s): Satish V. Shirolkar, Mukund.G. Tawar, Nishant. S. Gandhi, Nilesh B Deore
Various approaches have been used to retain the dosage form in the stomach as a way of
increasing the gastric residence time (GRT), including floatation systems; high-density systems;
mucoadhesive systems; magnetic systems; unfoldable, extendible, or swellable systems; and
superporous hydrogel systems. The aim of this study was to prepare and evaluate floating
microspheres of Pioglitazone hydrochloride for the prolongation of gastric residence time. The
microspheres were prepared by emulsion solvent diffusion-evaporation method using ethyl
cellulose and HPMC K100M. A full factorial design was applied to optimize the formulation.
Preliminary studies revealed that the concentration of polymer and stirring speed significantly
affected the characteristics of floating microspheres. The optimum batch of microsphere
exhibited smooth surfaces with good flow and packing properties, prolonged sustained drug
release, remained buoyant for more than 10 hrs, high entrapment efficiency upto 97%w/w.
Scanning electron microscopy confirmed the hollow structure with particle size in the order of
190 �Ž�¼m. The studies revealed that increase in concentration of hydrophillic polymer (HPMC)
increased the drug release from the floating mcirospheres. The results of 32 full factorial design
revealed that the concentration of ethylcellulose 10 cps (X1) and stirring speed (X2) significantly
affected drug entrapment efficiency, percentage release after 8 h and particle size of
microspheres.
