Determination of valsartan and amlodipine in valsartan and amlodipine tablets by HPLC

Objective To establish an HPLC method for the determination of valsartan and amlodipine in valsartanand amlodipine Tablets.Methods Waters symmetry C18(3.9 mm×150 mm,5 μm)was used.The mobile phase was composed of acetonitrile∶ methanol∶ triethylamine solution(adjusted with phosphoric acid to a pH of 4.3±0.1) 15∶ 35∶ 50.The flow rate was 1.0 ml·min-1 and detection wavelength 237 nm.The temperacture was 30℃.The sample solution concentrations were amlodipine 5 mg·L-1,valsartan 160 mg·L-1.Results Valsartan concentration achieved good linearity in the range of 128.32~192.48 mg·L-1,n =5,r=0.999 7,amLodipine in the range between 2.00 and 12.00 mg·L-1,n=5,r=0.999 3.The average recoveries of valsartan and amlodipine were 99.93%,99.85%,and RSD were 0.30% and 0.34%.Conclusion This assay is simple,rapid,sensitive,accurate and reliable.