Comparative Pharmacokinetics of Two Tablet Formulations of Amoxicillin: Bioequivalence Assessment

Abstract

The aim of the present study was to compare the bioavailability of amoxicillin (CAS 26787-78-0) from two different amoxicillin tablets (Demoksil^© 1 g tablet as test preparation and 1 g tablet of the originator product as reference preparation). The study was conducted according to an open-label, randomised two-period cross-over design with a wash-out phase of 4-7 days.

Blood samples for pharmacokinetic profiling were taken up to 10 h post-dose, and amoxicillin plasma concentrations were determined with a validated LC-MS/ MS method.

Maximum plasma concentrations (C_max) of 13,296.4 ng/ml (test) and 12,797.7 ng/ml (reference) were achieved. Areas under the plasma concentration-time curve (AUC_0→∞)of 39,556.7 ng · h/ml (test) and 38,599.1 ng · h/ml (reference) were calculated. The median t_max was 1.62 h (test) and 1.54 h (reference). Plasma elimination half-lives (t_1/2) of 1.64 h (test) and 1.65 h (reference) were determined. Both primary target parameters, AUC_0→∞ and C_max were tested parametri-cally by analysis of variance (ANOVA) and the 90% confidence intervals were between 96.76%-108.46% (AUC_0→∞)and 97.80%-111.98% (C_max). Bioequivalence between test and reference preparation was demonstrated since for both parameters, AUC and C_max the 90% confidence intervals of the T/R-ratios of logarithmically transformed data were in the generally accepted range of 80%-125%.

Key words

Amoxicillin, bioequivalence, pharmacokinetics - Antibiotics - CAS 26787-78-0 - CAS 61336-70-7 - Demoksil©