Partial least-squares method in analysis by differential pulse polarography. Simultaneous determination of amiloride and hydrochlorothiazide in pharmaceutical preparations Original Research Article

A method is proposed for the simultaneous determination of amiloride and hydrochlorothiazide in pharmaceutical preparations using differential pulse polarography in the presence of oxygen and partial least-squares (PLS) for calibration. The experimental variables that influence the system (pulse height, pulse delay and pH) are optimized by using response surface methodology to relate the variables to be optimized to the mean relative square error of prediction (RSEP), which is minimized. The proposed method was used to determine the two drugs in synthetic mixtures and pharmaceutical preparations. The results were validated by comparison with HPLC, with errors less than 10% in all instances.