Comparative bioavailability of two tablet formulations of metoclopramide hydrochloride

This investigation was carried out to evaluate the bioavailability of a new tablet formulation of metoclopramide hydrochloride (10 mg), Metosil relative to a recognized product, Plasil BP. The two brands were found to be similar in assay and content uniformity and both met the BP requirements of disintegration time. The bioavailability was carried out on 18 healthy male volunteers who received a single dose (2 x 10 mg) of the test (T) and the recognized (R) products in a randomized balanced 2-way crossover design. After dosing, serial blood samples were collected for a period of 8 hours. Plasma harvested from blood was analyzed for metoclopramide by a sensitive and validated high-performance liquid chromatographic assay. The maximum plasma concentration (Cmax), area under the plasma concentration curve up to the last measurable concentration (AUC0-t), and to infinity (AUC0-00) were analyzed statistically under the assumption of a multiplicative model. The time to maximum concentration (Tmax) was analyzed assuming an additive model. The parametric confidence intervals (90%) of the mean values of the pharmacokinetic characteristics (AUC0-t AUC0-00 and Cmax) for T:R ratio were in each case well within the bioequivalence acceptable range of 0.8-1.25. The test formulation was found bioequivalent to the reference formulation by the Schuirmann's 2 one-sided t-tests and by Wilcoxon-Mann-Whitney 2 one-sided tests procedure. Therefore, the two formulations were considered to be bioequivalent.