Determination of Lisinopril in Pure and Tablet form by Using 2-Hydroxynaphthaldehyde as Derivatizing Reagent

Abstract

An easy, sensitive and accurate spectrophotometric method has been developed for the determination of Lisinopril (LNP) in pure and tablet formulations based on derivatization reaction with 2-hydroxynaphthaldehyde (2HNA). The derivatization reaction was carried out in methanol solvent at pH-5.5 at 95±2C for 15 min. The linear calibration curve was obtained that obeyed the Beer’s law within the concentration range 5-50 μgmL^-1 of LNP at 433 nm with a coefficient of determination R²=0.996. The recovery was in the range from 98.25-101.82 with molar absorptivity of drug 9×10³ mole^-1cm^-1. The method was accurate and precise (intra-day variation 0.05-0.97% and inter-day 0.07-1.6%), with limit of detection (LOD) and limit of quantification (LOQ) 0.264 μgmL^-1 and 0.8 μgmL^-1, respectively. No interferences from the excipients were detected. The method was applied for the rapid analysis of LNP in pharmaceutical products