Comparative bioavailability of two cefadroxil formulations in healthy human volunteers after a single‐dose administration

Objective . To compare the bioavailability of two cefadroxil capsule (500 mg) formulations (Cefadroxila from Eurofarma Laboratórios Ltd, Brazil, as test formulation and Cefamox® from Bristol–Myers Squibb, Brazil S.A. as reference formulation) in 24 volunteers of both sexes. Material and methods . The study was conducted open with randomized two‐period crossover design and a 1‐week washout period. Plasma samples were obtained over a 12‐h interval. Cefadroxil concentrations were analysed by combined reversed‐phase liquid chromatography and tandem mass spectrometry (LC‐MS‐MS) with positive ion electrospray ionization using a selected ion monitoring method. From the cefadroxil plasma concentration versus time curves the following pharmacokinetic parameters were obtained: AUC last , AUC 0–∞ and C max . Results . Geometric mean of Cefadroxila/Cefamox® 500 mg individual percent ratio was 103.97% for AUC last , 104.08% for AUC 0–∞ and 95.23% for C max . The 90% confidence intervals (CI) were 98.14–110.16%, 98.37–110.12%, and 85.59–105.96%, respectively. Conclusion . Since the 90% CI for C max , AUC last and AUC 0–∞ were within the 80–125% interval proposed by the Food and Drug Administration, it was concluded that the Cefadroxila 500 mg capsule was bioequivalent to the Cefamox® 500 mg capsule, according to both the rate and extent of absorption. Copyright © 2000 John Wiley & Sons, Ltd.