Validated Spectrophotometric Method for Simultaneous Estimation of Hydrochlorothiazide and Candesartan Cilexetil in Tablet Dosage Form

A method for the simultaneous determination of hydrochlorothiazide and candesartan cilexetil in bulk and tablet dosage form was developed. The method employs formation and solving of simultaneous equations using 225.8 and 255 nm as two analytical wavelengths. The absorbance maxima of hydrochlorothiazide and candesartan cilexetil were found to be 225.8 nm and 255 nm respectively in methanol. The linearity range lies between 1-7 μg/ml for hydrochlorothiazide and 2-10 μg/ml for candesartan cilexetil at their respective wavelength. Both the drugs obey Beer's law. The molar absorptivity and sandell's sensitivity were found to be 4.11×10⁴ and 0.0073 respectively for Hydrochlorothiazide and for Candesartan cilexetil 6.21×10⁴ and 0.0098 respectively. The recovery studies confirmed the accuracy of the developed method.