Title: Stability Indicating Simultaneous Validation of Telmisartan and Cilnidipine with Forced Degradation Behavior Study by RP-HPLC in Tablet Dosage Form
Abstract: A simple, precise, and accurate RP-HPLC method has been developed and validated for the simultaneous assay of Telmisartan and Cilnidipine in tablets. Isocratic RP-HPLC method was developed on Waters C18 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mn>250</mml:mn><mml:mo>×</mml:mo><mml:mn>4.6</mml:mn></mml:math> mm, 5 μ m column using mobile phase as acetonitrile (ACN): buffer pH 3.0 with orthophosphoric acid (68 : 32) at a flow rate of 1.0 mL/min and the detection was carried out at 245 nm using photodiode array detector. Forced degradation study was carried out by oxidation, hydrolysis, photolysis, and heating the drug. The method was validated for specificity, linearity, precision, accuracy, robustness, and solution stability. The method was found to be linear in the concentration range of 40–160 μ g/mL with correlation coefficient of 0.9990 for Telmisartan and 10–40 μ g/mL with correlation coefficient of 0.9989 for Cilnidipine. Degradation products produced as a result of stress studies did not interfere with the detection of agomelatine; therefore, the assay can be considered to be stability indicating.