Comparative bioavailability of three commercially available cimetidine tablet formulations in healthy male volunteers

ABSTRACT

This investigation was carried out to evaluate the relative bioavailability of two different marketed 400 mg cimetidine tablets [cimedine' and citius'] compared to the innovator product [Tagamet, 400 mg tablet]. The three brands were found to be similar in assay average weight, weight uniformity, disintegration time and dissolution tests as specified in the USP XXII. The bioequivalency study was carried out on twelve healthy male volunteers who received a single oral dose [400 mg tablet] of each of the three formulations in the fasting state, in a randomized balanced three way crossover design. After dosing, serial blood samples were collected for a period of 8 hours. Cimetidine plasma concentrations were determined using a sensitive and validated high-performance liquid chromatographic [HPLC] assay. The maximum plasma concentration [Cmax] time to maximum concentration [Tmax] area under the plasma concentration time curve up to the last measurable concentration [AUCO-T], and to infinity [AUCO-OO], the elimination rate constant [Kel] and elimination halflife [t1/2] were analyzed statistically using analysis of variance [ANOVA] and the least significant difference [LSD] method. No statistically significant differences were found between the three brands in any of the calculated parameters. Therefore, the three formulations are considered bioequivalent