FORMULATION, DEVELOPMENT AND EVALUATION OF GASTRORETENTIVE FLOATING TABLETS OF BETAHISTINE USING NATURAL POLYMER
Betahistine a 3-hydroxy-3-methyl glutyrylcoenzymeA (HMG coA) reductase inhibitor is a statin with well-known lipid lowering effects that decreases cardiovascular morbidity and mortality in patients with and without coronary artery diseases. Floating drug delivery systems are the gastroretentive forms that precisely control the release rate of target drug to a specific site which facilitate an enormous impact on health care. This can be achieved by use of various polymeric substances including natural polymers. These polymers are inexpensive, safe and available in a variety of structures with versatile characteristics. The purpose of this research was to develop a novel gastro retentive drug delivery system based on direct compression method for sustained delivery of active agent to improve the bioavailability, reduce the number of doses and to increase patient compliance. Gastro retentive floating tablets of betahistine were prepared by direct compression method using altered concentrations of HPMC K4, HPMC K15 and gaur gum as polymers. The prepared tablets of betahistine were evaluated for hardness, thickness, friability, weight variation, drug content uniformity, buoyancy lag time, total floating time, in-vitro dissolution study, etc. All the compositions were resulted in adequate Pharmacopoeial limits. Compatibility studies was execution during FTIR shown that there was absence of probable chemical interaction between pure drug and excipients. The varying concentration of gas generating agent and polymers was found to effect on in-vitro drug release and floating lag time. In vitro drug release of floating gastro retentive tablet of betahistine shown that the formulation F8 was found to be the best formulation as it releases 99.45% betahistine in a controlled manner for an extended period of time (up to 12 hrs). The release data was fitted to various mathematical models such as higuchi, korsmeyer-peppas, first order and zero order to evaluate the kinetics and mechanism of the drug release. The Optimized formulation (F8) showed no significant change in physical appearance, drug content, floating lag time, in vitro dissolution studies after 75%±5% RH at 40±20C relative humidity for 6 months. Prepared floating tablets of betahistine may prove to be a potential candidate for safe and effective controlled drug delivery over an extended period of time for gastro retentive drug delivery system