Spectrophotometric Determination of Lisinopril Drug by Oxidative Coupling Reaction with 4-aminonaphthalene-1- sulfonic acid Reagent

Abstract

A simple, rapid and sensitive spectrophotometric method for determination of Lisinopril (LS) in both pure form and pharmaceutical preparations has been reported. The adapted technique based on utilization 4-aminonaphthalene-1-sulfonic acid as a Chromogenic reagent through an oxidative coupling reaction with Lisinopril and Potassium Peroxydisulfate (oxidation agent) in acidic medium to form green dye soluble product absorption maxima at 612 nm. Linearity was in the range 2–43 μg ml-1. The values of molar absorption coefficient (ε), correlation coefficient and Sandel’s index were found to be 10.3808 × 103 L. mole-1 cm-1, 0.9995 and 0.00343 µg.cm-2 respectively. The average of recovery % was 100.067. Detection Limit and quantitative limit were 0.0343 µg/ml and 0.1143 µg/ml. The proposed method has been successfully applied in the determination of preparations containing lisinopril.