Stability - Indicating LC Method for the Simultaneous Determination of Olmesartan and Ramipril in Dosage Form

A simple, rapid, and precise method is developed for the quantitative simultaneous estimation of Olmesartan (OL) and Ramipril (RAM) in combined pharmaceutical dosage form. A chromatographic separation was achieved with YMC Pack ODS A (250 x 4.6 mm) analytical column. The mobile phase composed of buffer, acetonitrile and methanol (50:40:10 v/v/v). The buffer used in the mobile phase is 0.1M sodium perchlorate monohydrate in double distilled water and pH adjusted 3.0 with trifluoroacetic acid. The instrumental settings are flow rate of 1.0 mL/min, column oven temperature at 30°C and detector wavelength of 210 nm using a photodiode array detector. The resolution between OL and RAM founds to be more than 4. Theoretical plates for OL and RAM were 16599 and 15900 respectively. Tailing factor for OL and RAM was 1.11 and 1.14 respectively. Capacity factor for OL and RAM was 3.14 and 3.60 respectively. OL, RAM and combination drug product were exposed to thermal, light, hydrolytic and oxidative stress conditions, and the stressed samples were analysed by the proposed method. The proposed method was found to be suitable and accurate for quantitative determination and stability study of OL and RAM in pharmaceutical preparations.