Simultaneous spectrophotometric and volumetric determinations of amoxycillin, ampicillin and cloxacillin in drug formulations: reaction mechanism in the base catalysed hydrolysis followed by oxidation with iodate in dilute acid solution

Abstract

A method for the analysis of degraded products of amoxycillin, ampicillin and cloxacillin in drug formulations, obtained as a result of their base hydrolysis is described. Simultaneous spectrophotometric and volumetric determinations of the antibiotic is based on the neutralization of the degraded product by dilute hydrochloric acid to get a pH ∼2 to be conducive for redox titration using potassium iodate as titrant. A red purple colour is developed in carbon tetrachloride at the end point. Spectrophotometry is done after separating the organic layer and measuring the absorbance of red-purple colour at λ max 520 nm. The pathways of different degraded products and their oxidation mechanism is described on IR, TLC and UV spectroscopic studies.