Abstract

FIRST DERIVATIVE SIMULTANEOUS DETERMINATION OF LOSARTAN POTASSIUM AND ENALAPRIL MALEATE IN BULK DRUGS AND TABLET FORMULATIONS

Karajgi Santosh Raveendra* and Kulkarni Raghavendra Vinayakrao

ABSTRACT

An accurate, reproducible, economical, rapid and simple UV-first derivative method for the simultaneous estimation of Losartan potassium and Enalapril maleate has been developed because there were no first derivative spectrophotometric methods reported for the determination of these drugs simultaneously. The method of determination is based on the zero crossing method, in which Losartan potassium can be determined without the interference of Enalapril maleate at 209nm wavelength (zero crossing point of Enalapril maleate) and Enalapril maleate can be determined without the interference of Losartan potassium at 245nm (zero crossing point of Losartan potassium). The linearity range for Losartan potassium and Enalapril maleate is 4-32μg/ml and 4-56μg/ml respectively. The equation for straight line for Losartan potassium is 0.003934x+0.0059 and for Enalapril maleate is 0.00173x+0.00454 as determined by method of least squares. Correlation coefficient was found to be within acceptable limits; 0.9992 and 0.9991 for Losartan potassium and Enalapril maleate respectively. The reported method can be applied for the routine determination of these drug combinations simultaneously in bulk drugs and tablet formulations without the interference of common excipients.

Keywords: Losartan potassium, Enalapril maleate, simultaneous estimation, first derivative spectrophotometric, zero crossing method, spectrophotometric determination.