RAPID RP-HPLC METHOD FOR SIMULTANEOUS SEPARATION AND ESTIMATION OF METOPROLOL AND AMLODIPINE IN COMBINATION TABLET FORMULATION

The aim of the present work was to develop a RP-HPLC method for simultaneous separation of Metoprolol and Amlodipine and validate the developed method for quantitative determination of the above said drugs in combination tablet dosage form. A simple, rapid, validated chromatographic method was developed for separation and determination of metoprolol and amlodipine in tablet preparations. The anti-hypertensive agents were separated using Welchrom RP-C18 Column (4.6 mm X 250 mm, 5 µ), Shimadzu LC-20 AT Prominence Liquid Chromatograph and the mobile phase constituted of 10 mM Phosphate buffer (pH 3.0): acetonitrile (50:50, v/v). The flow rate was 1.0 mL/min and the analyses were performed using Shimadzu SPD-20A Prominence UV-Visible detector at 235 nm. The separation of the anti-hypertensive agents, Metoprolol and Amlodipine was achieved within 5 minutes. Metoprolol and Amlodipine eluted at retention times of 2.690 minutes and 3.797 minutes respectively. The drugs obeyed Beer’s law in the concentration range of 5 - 25 µg/mL for metoprolol and 1 - 5 µg/mL for amlodipine. The developed assay method was found to be selective, precise and accurate. The method has been successfully applied for determination of Metoprolol and Amlodipine in pharmaceutical combination tablet dosage form. This developed method is sensitive, fast, and simple with excellent peak symmetry and high resolution