Bioequivalence evaluation of three different oral formulations of ciprofloxacin in healthy volunteers.

Two bioequivalence studies were performed in twenty four healthy male volunteers with the objective of comparing the bioavailability of three different oral formulations of ciprofloxacin as immediate release tablets 250, 500 and 750 mg (test formulations) with a reference formulation at 500 and 750 mg strengths forms. In study 1, the subjects were enrolled in a single-dose, open-label, 3-period, crossover randomised study, designed to compare the bioavailability of two test formulations of ciprofloxacin (A and B) as 250 and 500 mg tablets, compared to the reference formulation (C), as 500 mg tablets. In study 2, the same 24-subjects were included in a single-dose, open-label, 2-period, crossover randomised study, designed to compare the bioavailability of one test formulation of ciprofloxacin (A) as compared to the reference formulation (B), both products as 750 mg tablets. In both studies multiple blood samples were collected over 24 hours post-dosing. One washout period of six days was observed between the periods. Plasma was harvested and assayed for ciprofloxacin using a selective and sensitive high-performance liquid chromatography (HPLC) method with UV detection. The pharmacokinetic parameter values of Cmax and tmax were obtained directly from plasma data, ke was estimated by log-linear regression, and AUC was calculated by trapezoidal rule. Different statistical tests were performed on the basis of untransformed and log-transformed data and the overall residual variance from ANOVA. Assuming the accepted tolerance intervals, a beta-error of 20% and 90% confidence intervals (alpha = 0.10) of all the generally accepted tests (Westlake, Schuirmann test and Wilcoxon-Tukey nonparametric tests) showed that the formulations can be considered as bioequivalent with respect to the extent of absorption, given by the AUC0-infinity and with respect to rate of absorption as assessed by Cmax and tmax.

Comparative bioavailability of two immediate release tablets of enalapril/hydrochlorothiazide in healthy volunteers.

A bioequivalence study of two oral formulations of 20/12.5 mg tablets of enalapril/hydrochlorothiazide was carried out in 20 healthy male volunteers according to a single dose, two-sequence, crossover randomized design. One washout period of nine days was observed between the two periods. Multiple samples were collected over 96 hours post-dosing. Bioavailability was evaluated on the basis of plasma concentrations of enalapril and its main active metabolite, enalaprilat and hydrochlorothiazide. Plasma samples were assayed for enalapril, enalaprilat and hydrochlorothiazide using a selective and sensitive high-performance liquid chromatography method with mass spectrometry detection (LC-MS). The pharmacokinetic parameter values of Cmax and tmax were obtained directly from plasma data, k(e) was estimated by log-linear regression, and AUC was calculated by trapezoidal rule. Different statistical tests were performed on the basis of untransformed and log-transformed data and the overall residual variance from ANOVA. Assuming the accepted tolerance intervals, a beta-error of 20% and 90% confidence intervals (alpha = 0.10), all the generally accepted tests (Schuirmann test and Wilcoxon-Tukey and Hauschke nonparametric tests) showed that the formulations can be considered as bioequivalent with respect to the extent of absorption, given by the AUC(0-infinity) and with respect to rate of absorption as assessed by Cmax and tmax.