Formulation of Verapamil Hydrochloride Matrix Granules by Sintering Technique and its Evaluation

Abstract

Exploration of sintering concept in the pharmaceutical sciences is relatively recent. The aim of this study was to investigate the release characteristics of matrix granules consisting of hydrophobic ( i.e waxy ) material and Verapamil hydrochloride for sustained release application using thermal sintering technique. It was considered as an ideal drug for designing sustained release formulation on account of its high frequency of administration and short biological half life. Granules prepared by melt granulation technique were formulated with water soluble drug, carnauba wax, glyceryl behenate ( a wax matrix forming polymer ) lactose, magnesium stearate. Matrix granules of Verapamil hydrochloride prepared with various concentration of wax and polymer were sintered thermally at various times periods, temperature and were evaluated for physicochemical parameters and in vitro dissolution studies. The sintering time markedly affected the drug release properties of wax and polymer. It is notable that the release rate of Verapamil hydrochloride from granules was inversely related to the time of sintering. Sintering technique enhanced the extend of drug retardation from the systems studied.