Metronidazole

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.

Colon-specific drug delivery has gained increased importance in the delivery of drugs for the treatment of local diseases associated with the colon, such as Crohn's disease, ulcerative colitis, colorectal cancer and amoebiasis. Metronidazole, an antiprotozoal drug is clinically effective in colonic diseases, both locally and systemically. The aim of this work was to prepare and evaluate Eudragit coated chitosan microspheres of metronidazole for colon targeting. Chitosan microspheres were prepared by emulsion dehydration method using different ratios of drug and polymer. Eudragit coated chitosan microspheres were performed by solvent evaporation method and were evaluated for percentage yield, flow property, particle size analysis, surface morphology, determination of drug content, drug entrapment efficiency, degree of swelling, in vitro drug release and its kinetic profile. The percentage yield of all formulations was more than 80%. The microspheres showed a spherical structure with a smooth surface morphology. The drug entrapment efficiency was found to be in between 68.8%-81.6%. The in vitro release was found to be in following order F3>F1>F2>F4>F5>F6. In the case of F3 only 13.03% of the drug was released in 5 hrs, but it showed high and fast increase in drug release from 6th hr in pH 6.8 phosphate buffer. It shows 90.52% drug release after 12hrs.The formulations gave good fit to the Zero order and the mechanism of drug release was diffusion. The results clearly demonstrated that the Eudragit S100 coated metronidazole chitosan microspheres is a potential system for colon-specific drug delivery.