Development and Validation of RP-HPLC Method for Simultaneous Estimation of Triamterene and Benzthiazide in Tablets

A specific, accurate, precise and reproducible RP-HPLC method has been developed and subsequently validated for the simultaneous determination of Triamterene and Benzthiazide in tablets. The proposed HPLC method utilizes BDS hypersil (Thermo scientific) C18 column (250 mm × 4.6 mm id, 5 μm particle size), and mobile phase consisting of phosphate buffer: methanol (70:30) and pH adjusted to 3.5 with sodium hydroxide and flow rate of 1.0 ml/min. Quantitation was achieved with UV detection at 245 nm based on peak area with linear calibration curves at concentration ranges 10-30 μg/ml for Triamterene and 5-15 μg/ml for Benzthiazide. The retention time of Triamterene and Benzthiazide were found to be 5.960 min and 3.493 min respectively. The method was validated in terms of accuracy, precision, linearity, limits of detection, limits of quantitation and robustness. This method has been successively applied to tablet formulation and no interference from the formulation excipients was found.