Application of the Bivariate Calibration for Simultaneous Determinations of Hydrochlorothiazide/Enalapril Maleate and Hydrochlorothiazide/Bisoprolol Fumarate in Drug Tablets

The bivariate calibration method was used for quantification of hydrochlorothiazide/enalapril maleate and hydrochlorothiazide/bisoprolol fumarate in pharmaceutical tablets. The determination of hydrochlorothiazide/enalapril maleate is made using new absorption wavelengths at 211 and 272 nm, while hydrochlorothiazide/bisoprolol fumarate is made at new wavelengths 273.5 and 293 nm. The results are compared favorably to those obtained from HPLC. The method is simple, time saving, and costly effective; it could be used to determine the pharmaceutical compounds in commercial available products.