Objective: The aim of this study was to evaluate the performance of 2 phenoxymethylpenicillin 500,000 UI tablet formulations in healthy human volunteers. Material and methods: The study was conducted using an open, randomized crossover design with a 7-day washout interval. A single dose of each formulation was administered to 26 healthy volunteers as assessed by clinical and laboratory test evaluations. The plasma samples were obtained over an 8-h interval and phenoxynethylpenicillin concentrations were quantified by a suitable and validated HPLC-UV method with detection at 220 nm. Systolic and diastolic blood pressure and pulse rate measurement were taken pre dose and at intervals up to 8 h. Results: Tolerance of both products was adequate. The mean of Meracilina/Pen-Ve-Oral 500,000 UI% geometric mean was 99.89% for AUC(0-t), 100.86% for AUC(0-infinity). and 101.11% for C-max. The 90% confidence intervals were 94.62 - 105.46%, 95.22 - 106.83% and 98.61 - 103.87%, respectively. The mean recovery of phenoxymethylpenicillin was 94.8%, while the retention time observed for phenoxymethylpenicillin and phenytoin (internal standard) was 4 and 10 min, respectively. The limit of quantification was 0.10 mg/l. Conclusion: Since the 90% CI for AUC(0-t), AUC(0-infinity) and C,a, ratios were all within the 80 - 125% interval proposed by the US FDA and accepted by ANVISA, it was concluded that the Meracilina formulation (manufactured by Ache S.A.) is bioequivalent to Pen-Ve-Oral (manufactured by Eurofarma) for both the rate and the extent of bioavailability.451266967
