A method for the simultaneous determination of enalapril maleate and hydrochlorothiazide in pharmaceutical formulations (tablets) is described. The procedure is based on the use of the high-performance liquid chromatography (HPLC), and of the second-derivative ultraviolet spectra, by utilizing the linear relationship between substances concentration and derivative peak amplitude. The minimum concentration detectable by derivative spectrophotometry was 1 μg ml−1 for both drugs, and by HPLC 50 ng ml−1 for hydrochlorothiazide and 100 ng ml−1 for enalapril maleate. The relative standard deviations observed were approx. 2% for derivative spectrophotometry, and 1.5% for HPLC. The proposed methods, which give thoroughly comparable data, are simple and rapid, and allow precise and accurate results.
Simultaneous determination of enalapril maleate and hydrochlorothiazide in tablets by derivative UV spectrophotometry and high-performance liquid chromatography
CARLUCCI, Giuseppe;MAZZEO, PIETRO
1993-01-01
Abstract
A method for the simultaneous determination of enalapril maleate and hydrochlorothiazide in pharmaceutical formulations (tablets) is described. The procedure is based on the use of the high-performance liquid chromatography (HPLC), and of the second-derivative ultraviolet spectra, by utilizing the linear relationship between substances concentration and derivative peak amplitude. The minimum concentration detectable by derivative spectrophotometry was 1 μg ml−1 for both drugs, and by HPLC 50 ng ml−1 for hydrochlorothiazide and 100 ng ml−1 for enalapril maleate. The relative standard deviations observed were approx. 2% for derivative spectrophotometry, and 1.5% for HPLC. The proposed methods, which give thoroughly comparable data, are simple and rapid, and allow precise and accurate results.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
