Comparative bioavailability of two oral formulations of levofloxacin in healthy Mexican volunteers

Objective: To assess the bioequivalence of two levofloxacin 500 mg tablets marketed in Mexico. Material and methods: The clinical investigation was designed as a randomized, open-labeled, two-part, two-treatment, two-period crossover study, in 27 healthy male volunteers. 1 tablet of each formulation was administered with 200 ml of water after 10 h overnight fast. After dosing, serial blood samples were collected for a period of 24 h. Plasma concentrations were determined by a validated high-performance liquid chromatographic method and pharmacokinetic parameters were obtained by non-compartmental approach. Analysis of variance (ANOVA) was carried out using log-transformed AUC_last, AUC_∞ and C_max and untransformed t_max, and 90% confidence intervals for AUC_last, AUC_∞ and C_max were calculated. If the 90% confidence intervals (CI) for AUC_last, AUC_∞ and C_max fell fully within the interval 80-125%, the bioequivalence of the two formulations was established. Results: The means (test and reference) for AUC_last were 58.869 and 56.297 μg × h/ml, for AUC_∞ were 63.456 and 60.748 μg × h/ml and for C_max were 8.691 and 8.445 μg/ml. The geometric mean ratios of the test formulation to reference formulation for AUC_last, AUC_∞ and C_max (CI) were 104.53% (102.73-106.36%), 104.37% (102.04-106.75%) and 103.45% (95.57-111.97%), respectively. All 90% CI for AUC_last, AUC_∞ and C_max fell within the Mexican Federal Commission for Prevention of Sanitary Risks (COFEPRIS) accepted bioequivalence range of 80-125%. Conclusions: Based on the results, the formulations tested are bioequivalent.