Formulation and evaluation of floating tablet of rosiglitazone malate

Abstract

Rosiglitazone Maleate is used for the management of type-2 diabetes. It is an absorption window limited drug, whose solubility decreases with increase in the pH and has a short half life of 3-4 h. Therefore the present investigation is concerned with the development of the floating matrix tablets, which after oral administration were designed to prolong the gastric residence time and thus to increase the bioavailability of the drug and its half life. Rosiglitazone Maleate showed maximum absorption at wavelength 222 nm in 0.1N HCl. Drug-polymer compatibility studies by DSC gave conformation about their purity and showed no interaction between drug and selected polymers. Various formulations were developed by using release rate controlling and gel forming polymers like HPMC, NaCMC and Carbopol-934 in single and combinations by direct compression method with the incorporation of sodium bicarbonate as gas generating agent. All the formulations had floating lag time below 4 minutes and constantly floated on dissolution medium for more than 12 h. Swelling studies indicated significant water uptake and contributed in drug release. DCP showed maximum drug release retardation compared to lactose and MCC. From among all the developed formulations, as F7, F14 and F21 prolonged the drug release for longer period of time, they were nominated as best formulations. The best formulations followed power law kinetics while the drug release mechanism was found to be anomalous type, diffusion through the honeycomb network and polymer relaxation. The best formulations were found to be stable during stability studies for two months. Thus, best formulations satisfied physico-chemical parameters, floating time, swelling index and in vitro drug release profile requirements for a floating drug delivery system.