Absorption Correction Spectrophotometric Method for Simultaneous Estimation of Torsemide and Amiloride Hydrochloride in Their Combined Dosage Form

A new sensitive, simple, rapid and precise spectrophotometric method has been developed for simultaneous estimation of Torsemide and Amiloride HCl in pharmaceutical dosage form. This method was based on UV spectrophotometric determination of two drugs, using absorbance correction method. It involves measurement of absorbances at two wavelengths 288nm(λmax of Torsemide (TOR)) and 361nm (λmax of Amiloride HCl (AMI)) in methanol for the simultaneous quantitative determination of Torsemide and Amiloride HCl in the binary mixture without previous separation. The linearity was observed in the concentration range of 5 -25 μg/ml for Torsemide and 5-25 μg/ml for Amiloride HCl. The accuracy and precision of the method was determined and validated statically. The method showed good reproducibility and recovery with % RSD less than 2. Method was found to be rapid, specific, precise and accurate, can be successfully applied for the routine analysis of Torsemide and Amiloride HCl in combined dosage form without any interference by the excipients. The method was validated according to ICH guidelines.