RP-HPLC METHOD DEVELOPMENT AND VALIDATION FOR THE SIMULTANEOUS ESTIMATION OF ANTIHYPERTENSIVE DRUGS OLMESARTAN AND CILNIDIPINE IN BULK AND TABLET DOSAGE FORM

P. Harshalatha*, K.B.Chandrasekhar and M.V.Chandrasekhar

A new reversed-phase HPLC method was developed and subsequently validated for simultaneous estimation of antihypertensive drugs Olmesartan and cilnidipine in pharmaceutical dosage forms. Chromatography was carried out on Inertsil C-18 column (4.6 x 150mm, 5μ particle size) with a mobile phase composed of buffer and acetonitrile in 55:45%v/v and the mobile phase was pumped at a flow rate of 1.0 mL/min. Detection was carried out using a PDA detector at 225nm. Parameters such as linearity, precision, accuracy, recovery, specificity and ruggedness were studied as reported in the International Conference on Harmonization guidelines. The retention times for olmesartan and cilnidipine were 2.2 min and 3.7 min respectively. The linearity range for olmesartan and cilnidipine were 10-60 μg/mL and 5-30 μg/mL. The percentage recoveries of olmesartan and cilnidipine were 98.01% and 98.88%, respectively. This method can be employed for routine quality control of olmesartan and cilnidipine tablets in quality control laboratories and pharmaceutical industries.