RP-HPLC METHOD FOR SIMULTATANEOUS DETERMINATION OF AMLODIPINE BESYLATE, VALSARTAN, TELMISARTAN, HYDROCHLOROTHIAZIDE AND CHLORTHALIDONE: APPLICATION TO COMMERCIALLY AVAILABLE DRUG PRODUCTS

A simple, precise and stability-indicating HPLC method was developed and validated for the simultaneous determination of anti-hypertensive drugs Amlodipine Besylate, Valsartan, Telmisartan and diuretics Hydrochlorothiazide and Chlorthalidone. The separation was achieved on Cosmosil PAQ (150 mm × 4.6 mm) 5 μm column with gradient flow. The mobile phase at a flow rate of 1.0 mL min 1 consisted of 0.05 M sodium dihydrogen phosphate buffer and acetonitrile (Gradient ratio). The UV detection was carried out at 220 nm. The method was successfully validated in accordance to ICH guidelines. Further, the validated method was applied for commercially available pharmaceutical dosage form.