Simultaneous Determination of Amlodipine Besylate and Valsartan in Tablets by High Performance Liquid Chromatography with UV Detection

A simple, precise, accurate and sensitive high-performance liquid chromatography method with UV detection at 220 nm was developed for the simultaneous determination of Amlodipine and Valsartan drugs in pharmaceutical formulations. The present method presents a narrow range (19.6-78.4 (for Amlodipine) and 32-128 (for Valsartan) g/ml) of calibration curve and sensitivity. Isocratic separation was employed on a C18 column (250×4.6 mm i.d., 5 μm) at ambient temperature. The mobile phase consisted of water, acetonitrile and glacial acetic acid (300:700:1 by volume). The Drugs under investigation were found to be 93–101% recovery of their label claim in pharmaceutical formulations. The separation was completed within 6 minutes. The calibration curve was linear over the range of 19.6–78.4 µg/mL for Amlodipine and over the range of 32 to 128 µg/mL for Valsartan. The Limits of Quantification (LOQ) were chosen to be the lowest concentrations in the calibration curve (19.6 µg/mL) for Amlodipine and (32 µg/mL) for Valsartan. The Limits of Detection (LOD) were 10 µg/mL and 16 µg/mL for Amlodipine and Valsartan, respectively. Good method precision was demonstrated for the analysis with a coefficient of variation of 0.0049 and 0.002 for amlodipine and valsartan, respectively).