In-Vitro Release of Metronidazole from Suppositories Formulated with Blends of Cow Fat and Palm Kernel Oil

Abstract

The suitability of cow fat (CF) and palm kernel oil (PKO) blends as suppository bases was investigated using metronidazole as the model drug. Three blends of PKO and CF in the ratios of 1:2, 1:3 having melting points within acceptable range for suppository formulation were chosen. The suppositories including those of cocoa butter used as the Standard, were prepared by the fusion method and thereafter evaluated using the following parameters; appearance, weight uniformity, liquefaction time, absolute drug content and dissolution rate. The results of the evaluation indicated that the suppositories had uniform appearance and low variation in weight. Also the liquefaction times and absolute frug content contents and acceptable ranges. The release studies carried out in phosphate buffer solution (pH 7.2) showed that the 1:2 (PKO: CF) base blend suppositories had the fastest release rate but may only be suitable for use in the temperate regions due to its melting point, while the 1:3 and 2:3 base blend suppositories had the slowest release but can be comfortably used in the tropics. Blends of CF and PKO have bright prospects as good suppository bases.