effects of lubricants

The aim of the study was to evaluate the effect of different lubricants on pharmaceutical effectiveness of metronidazole tablets determined by the rate of release of drug from the dosage form. Different lubricants, like magnesium stearate, talc and the combination of both were used to prepare metronidazole tablets by direct compression method. The tablets were tested for quality control parameters such as uniformity of weight, thickness, diameter, contents assay, hardness, friability and disintegration time. Formulations were tested for the releasing pattern of drug from tablets by in-vitro dissolution test. Better results were achieved from formulation having magnesium stearate as lubricant based on compression force value. The content uniformity for all the three formulations was found in the range of 96.71 to 99.61%, while hardness was in the range of 7.39±0.341 to 10.375±0.95 Kg. The formulated tablets were also analyzed for dissolution profile which was more than 85% within 20 minutes. Then it was compared with dissolution profile of marketed products for quality and similarity analysis. Lubricant plays a key role in successful manufacturing of pharmaceutical solid dosage forms. Many failures in pharmaceutical manufacturing operations, directly or indirectly, can be controlled by appropriate screening of lubricants.