Comparative bioavailability of two tablet formulations of ibuprofen

This investigation was carried out to evaluate the bioavailability of a new tablet formulation of ibuprofen (600 mg), Profinal, relative to reference product, Brufen (600 mg) tablets. The 2 brands were found to be similar in assay, weight variation and dissolution as stipulated by the USP XXII, as well as the disintegration time, as specified by the BP 1988. The bioavailability was carried out on 18 healthy male volunteers who received a single dose (600 mg) of the test (T) and the reference (R) products in the fasting state, in a randomized balanced 2-way crossover design. After dosing, serial blood samples were collected for a period of 12 hours. Plasma harvested from blood was analyzed for ibuprofen 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-infinity) 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-infinity and Cmax) for T:R ratio were in each case, well within the bioequivalence acceptable range of 80-125%. The test formulation was found bioequivalent to the reference formulation by the Schuirmann's 2 1-sided t-tests and by Wilcoxon-Mann-Whitney 2 1-sided tests procedure. Therefore, the 2 formulations were considered to be bioequivalent.