Clarithromycin

Clarithromycin drug in the form tablet was formulated with different polymers. The object of the present work is preparing floating tablets in controlled fashion. The gas generating agent, sodium bicarbonate was added in different concentrations with varying amount of retardation polymers. Different grades of HPMC polymers HPMC K4M, K15M & K100M were used as retarding polymers. The formulation blend was evaluated for various physicochemical properties and all the parameters were found to be within limits. The formulations F1-F9 were formulated and evaluated for various quality control parameters. All the formulations were passed the tests and the results were within limits. From the dissolution data it was evident that formulation F7 was found to be best with maximum percent drug release of 96.90% upto 24 hours.

Gastroretentive systems have the unique quality to remain in the gastric region for several hours. Due to this they prolong the gastric residence time of the drug significantly. Floating microspheres possess the advantage of better flowing properties attributed to the use of low density polymers. Clarithromycin is a broad-spectrum antibiotic and extensively absorbed orally. It is used in the eradication of H. Pylori infection combined with an acid suppressing agent. Clarithromycin floating microspheres were prepared using polymer Ethyl Cellulose in different concentrations by solvent evaporation method. The FTIR studies showed no interaction between drug and polymers. The floating microspheres were evaluated for angle of repose, percentage yield, particle size, SEM, buoyancy percentage, drug content, percentage drug entrapment, in-vitro dissolution studies, kinetics of drug release and stability studies. Formulation F3 was found to be the best formulation showing the highest degree of sustained release that is 73.86% at the end of 12 hours. Formulations were seen to follow zero order release profile and Korsemeyer-Peppas model was the best fitting model. Marginal changes were observed in the drug content, buoyancy time and In-vitro dissolution studies which are insignificant. Storage conditions were carried out at 40±20C/75±5%RH for 6 months.

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.