Spectrophotometric Determination of Enalapril Using Tropeolin 00

Rapid and sensitive spectrophotometric method has been developed for the determination of Enalapril in pharmaceutical formulations. The method is based on the complex formation in acidic media (pH 2), using the Tropeolin 00 and hydrochloric acid. The formed complex is extractable with dichloromethane and shows a maximum absorbance at 415 nm, following the Lambert–Beer law in the concentration ranging between 10 and 100 μg/mL. The developed method has been statistically validated for application in pharmaceutical quality control at the laboratory scale and shows intraday and interday precision of 1.05 and 1.81% respectively. The recovery tests were ranged between 99.78 and 100.72 % and the detection limit was found at 2.03 μg/mL.