Simultaneous Determination of Amlodipine and Atorvastatin in Caduet® Tablets Using HPLC

A simple, selective, sensitive and precise, simultaneous high performance liquid chromatographic analysis of tablets containing amlodipine and atorvastatin was described. Good chromatographic separation was achieved using a Perfectsilr Target ODS-3 (4.6 cm × 250 mm, 5 µm) and a mobile phase consisting of acetonitrile-phosphate buffer pH 4.5 (55:45, v/v) at a flow rate 1ML min^-1. The ultraviolet detector was set at wavelength 237 nm. Amlodipine and atorvastatin were measured at 1.071 and 3.765 min, respectively. The linear ranges for amlodipine and atorvastatin were 1-10 and 5-50 µg mL^-1, respectively. The recoveries of amlodipine and atorvastatin in pharmaceutical preparation were all greater than 98.5% and their relative standard deviations were less than 2.0%. The limits of detection were 0.19 and 1.25 µg mL^-1 for amlodipine and atorvastatin, respectively.