Abstract

A simple, specific, accurate, precise and stability indicating RP-HPLC method was developed and validated for the simultaneous estimation of Metoprolol Succinate and Cilnidipine in bulk and pharmaceutical formulation . The method was developed using Enable C 18G column (250 ×4.6 mm, 0.5 μm) with mobile phase consisting of Acetonitrile and 0.01 M ammonium acetate (pH adjusted to 3.5 with acetic acid) in the ratio of 35:65 %v/v with a flow rate of 0.7 mL/min .UV detection was carried out at 265 nm. The retention time for Metoprolol Succinate and Cilnidipine were found to be 2.765 and 3.326 min respectively. The proposed method was validated for linearity, range, accuracy, precision, robustness, LOD and LOQ. Linearity was observed over a concentration range 2.5-30 μg/ml for Metoprolol Succinate (r2 =0.9978) and 0.5-50 μg/ml for Cilnidipine (r2 =0.9988). The % RSD for Intraday and Interday precision was found to be 0.28 and 0.18 for Metoprolol Succinate and 0.47 and 0.35 for Cilnidipine. The LOD and LOQ were found to be 0.12 μg/ml and 0.46 μg/ml for Metoprolol Succinate and LOD and LOQ were found to be 0.05 and 0.15 μg/ml for Cilnidipine repectively. Metoprolol Succinate and Cilnidipine were subjected to stress conditions of degradation including acidic, alkaline, oxidative, thermal and photolysis. The developed method was applicable for pharmaceutical formulations and can be used for routine quality control.