A simple and sensitive RP-HPLC method for simultaneous estimation of torsemide and spironolactone in combined tablet dosage form

Torsemide (TSM) is a loop diuretic used in the treatment of edema, and spironolactone (SPL) is a potassium-sparing diuretic used in hypokalemia. Both are potential diuretics used in combination to treat congestive heart failure. This paper describes a simple, sensitive, accurate, and validated reverse-phase high-performance liquid chromatographic (RP-HPLC) method for the simultaneous quantification of these compounds as the bulk drug and in tablet dosage forms. Separation was carried out on Jasco HPLC system equipped with Neosphere C8 column (150 × 4.6 mm i.d.) and UV/VIS detector using acetonitrile:10 mM potassium dihydrogen phosphate buffer in ratio of 60:40 (υ/υ) as the mobile phase, and detection was carried out at 240 nm. Results were linear in the range of 2–12 μg mL-1 for TSM and 5–30 μg mL-1 for SPL. The method was successfully applied for the analysis of drugs in pharmaceutical formulation. Results of the analysis were validated statistically and by recovery studies.