Design of Hydralazine Hydrochloride Matrix Tablets Based on Various Polymers and Lipids

Abstract

The purpose of this study was to design matrix tablets of hydralazine hydrochloride to overcome its side effects and to increase its bioavailability. Hydroxypropyl methylcellulose, carbomer, glyceryl dibehenate and cetyl alcohol were used in matrix tablets at various concentrations for sustained drug delivery. Compression and flow properties of powder mixtures were tested before tablets were compressed by direct compression method. Weight variation, diameter and thickness, hardness, tensile strength, friability % and disintegration time of tablets were tested for their physical characterization. Drug:excipient compatibility in tablets was investigated by Fourier Transform Infrared Spectroscopy and Differential Scanning Calorimetry. Determination method of drug in dissolution mediums was validated through following performance criteria: linearity, intra- and inter-day precision, accuracy, specifity and recovery. All formulations met compendial requirements and any chemical interaction between drug and tablet excipients was not detected. It was observed that waxy tablets released drug faster than polymer based tablets. The slowest drug release rate was obtained with carbomer matrix tablets followed by hydroxypropyl methylcellulose, glyceryl dibehenate and cetyl alcohol. Drug release met Higuchi kinetic model in general. While the mechanism of drug release from polymer based tablets was non-Fickian, waxy tablets generally displayed diffusionally controlled drug release.