Simultaneous determination of valsartan and amlodipine besylate by high performance capillary electrophoresis

A high performance capillary electrophoresis(HPCE) method was established for the simultaneous determination of valsartan and amlodipine.The background electrolyte system composed of 30 mmol/L phosphate buffer(pH=7.47) was found to be the most suitable solution for this separation at the detection wavelength of 237 nm,separation voltage of 15 kV and the injection of sample for 10 s.The linear calibration ranges were 0.050 4 to 0.504 0 mg/mL(r=0.999 8,n=6) for valsartan,and 0.050 4 to 0.504 0 mg/mL(r=0.999 6,n=6) for amlodipine besylate.The relative standard deviations(RSD)(n=6) of the migration time and peak-area counts of valsartan were 0.3% and 1.3% respectively,while amlodipine besylate 0.6% and 1.4%.The recoveries were determined to be 98.98%—99.79% for valsartan,98.22%—99.46% for amlodipine besylate.By using proposed HPCE method,valsartan and amlodipine besylate were well-separated within only 15.0 min(R=29.8).This method is rapid,sensitive and practical.