Novel Method for Determination of Captopril in Pharmaceutical Formulations by Cloud – Point Extraction

Abstract

A new, simple , fast and accurate spectrophotometric method for the determination of captopril in pure form and in pharmaceutical preparations is proposed by cloud point extraction . after complexation with bromo phenol blue used as complexing agent . using Triton X-114 as surfactant It is extracted and then separated into two phases, organic and aqueous by centrifugation and placed in an ice bath, then the aqueous layer is poured and the organic layer dissolves in the ethanol solvent, and the absorption is measured as it gives absorption at the wavelength 425 The optimum conditions for the reaction were studied, the triton x-114 volume, the acid volume, the reagent volume, the temperature and time affected on the cloud point extraction process, etc. To reach a high extraction of efficiency. It was found that the concentrations that obeyed Beer's law are in a linear range(1-12µg/ml), and the value of the correlation coefficient R²₌0.9959. The detection limit was calculated and was equal to (0.051µg/ml) and the method has been successfully applied to pharmaceutical preparations for captopril present in tablets containing known.