New stability indicating liquid chromatographic method for the estimation of Valsartan in pharmaceutical dosage forms

Valsartan is an orally active antihypertensive agent which belongs to the category of angiotensin II type I receptor antagonists. Valsartan is used for the treatment of heart failure, hypertension, myocardial infraction and diabetic nephropathy. A new stability indicating RP-HPLC was proposed for the quantification of Valsartan by using an ion-pairing agent, tetra butyl ammonium hydrogen sulphate. Mobile phase mixture consisting of 10 mM tetra butyl ammonium hydrogen sulphate and methanol (25: 75, v/v) was selected with a flow rate of 1 ml/min using Agilent C₁₈ column (Detection wavelength 250 nm). The LOD and LOQ were found to be 0.0291 μg/mL and 0.0897 μg/mL respectively. Linearity was observed over the concentration 0.1-50 μg/mL with linear regression equation, y = 36571x + 13532 and the method is precise, accurate and robust. Stress degradation studies were performed and the method was found to be selective and specific.