Spectrophotometric simultaneous determination of triamterene and hydrochlorothiazide in triamterene-H tablets by multivariate calibration methods.

The multivariate calibration methods of partial least-square regression and principal component regression were applied for the simultaneous spectrophotometry determination of triamterene (TRM) and hydrochlorothiazide (HYD) in their mixtures. The parameters of the chemometric procedure were optimized, and the proposed methods were validated with synthetic samples and applied to analyze these drugs in pharmaceutical products with good accuracy and precision. The results were compared with those given by the British Pharmacopoeia (BP) method. The square of the correlation coefficients (R(2)) for predicted TRM and HYD with the proposed method in a test sample were 0.9994 and 0.9992, respectively. The relative standard deviation for commercial tablets in the proposed method and BP standard method were 0.405 and 2.142%, respectively.