In- vitro buoyancy

In the present study, an attempt has been made to prepare floating microspheres of clarithromycin designed as gastroretentive dosage form for the treatment of Heliobacter pylori. The floating microspheres were  prepared using different polymers like HPMC- ethyl cellulose, HPMC, eudragit S-100, eudragit L-100, by solvent evaporation/diffusion methods which offer advantage of short processing time, lack of exposure of the ingredients to high temperature and gives high encapsulation efficiency. Formulations were characterized for their particle size, practical yield, entrapment efficiency, in vitro buoyancy, scanning electron microscopy (SEM) and in vitro drug release. Scanning electron microscopy shows that spherical microspheres with porous surface were formed. The optical microscopic studies revealed that the practical yield was more than 61.78% with a particle size range of 105.61-292.40 µm.  The percent entrapment efficiency is about 62.68% and more in larger particle as compared to smaller particle. The percent buoyancy was more than 74.10% up to 12 hours. The particle size, percent yield, percent drug entrapment and percent was increased significantly with increase in polymer concentration. The in vitro release was significantly decreased with in polymer concentration.  Hence it can be inferred that the floating microsphere of clarithromycin as a gastroretentive dosage form may prolong drug release thereby improving bioavailability and enhance opportunity of drug absorption in stomach to prevent degradation of drug under alkaline pH.