Simultaneous kinetic fluorimetric determination of amoxycillin and clavulanic acid by the stopped-flow mixing technique

Abstract

Kinetic methodology was applied to the resolution of mixtures of amoxycillin and clavulanic acid. The method thereby developed is based on the formation of fluorescent derivatives in the presence of cerium(IV) in an acidic medium, and the simultaneous determination is made possible by the difference between the reaction rates of the two analytes. By using the stopped-flow mixing technique, kinetic data can be obtained within a few seconds of the reactants mixing, which allows the proposed method to be readily applied to routine analyses. The calibration graphs were linear over the range 0.06–15.0 µg ml^–1 for amoxycillin and 0.10–17.5 µg ml^–1 for clavulanic acid. The relative standard deviation was less than 3%. Mixtures of amoxycillin and clavulanic acid in ratios between 6:1 and 1:4 were satisfactorily resolved. The proposed simultaneous method was applied to the determination of these compounds in pharmaceutical preparations.