Bioequivalence evaluation of two brands of ketoconazole tablets (Onofin-K® and Nizoral®) in a healthy female Mexican population

A randomized, crossover study was conducted in 24 healthy female volunteers to compare the bioavailability of two brands of ketoconazole (200 mg) tablets; Onofin-K(R) (Farm-aceuticos Rayere S.A., Mexico) as the test and NIZORAL(R) (Janssen-Cilag, Mexico) as the reference products. The study was performed at the Clinical Pharmacology Research Center of the Hospital General de Mexico in Mexico City. Two tablets (400 mg) were administered as a single dose with 250 ml of water after a 12 h overnight fast on two treatment days separated by a 1 week washout period. After dosing, serial blood samples were collected for a period of 12 h. Plasma harvested was analysed for ketoconazole by a modified and validated HPLC method with UV detection in the range 400-14000 ng/ml, using 200 mul of plasma in a full-run time of 2.5 min. The pharmacokinetic parameters AUC(0-t), AUC(0-alpha), C-max, T-max and t(1/2) were determined from plasma concentrations of both formulations and the results discussed. AUC(0-t), AUC(0-alpha) and C-max were tested for bioequivalence after log transformation of data, and no significant differences were found either in 90% classic confidence interval or in the Anderson and Hauck test (p<0.05). Based on statistical analysis, it is concluded that Onofin-K(R) is bioequivalent to Nizoral(R) . Copyright (C) 2004 John Wiley Sons, Ltd.