RP-HPLC Method Development and Validation for Simultaneous Estimation of Candesartan Cilexetil and Hydrochlorothiazide Tablet Dosage Form

A simple, accurate and sensitive RP-HPLC method was developed and validated for the determination of candesartan cilexetil and hydrochlorothiazide in tablet dosage form. The separation of the two drugs was achieved on a Reprospher 100 –C l 8 column (250 x 4.6 mm, 5 µm particle size) with UV detection at 260 nm. The mobile phase consists of two solution, solution (1) orthophosphoric acid (pH 2.2) and the solution (2) which is acetonitrile and purified water in the ratio 55: 45 v/v, respectively. The method was validated in terms of linearity, accuracy, precision, specificity, limit of detection, limit of quantitation and robustness. Linearity was observed in the concentration range 10-70µg/ml for hydrochlorothiazide and 12.8 -89.6µg/ml for candesartan cilexetil. The limit of quantitation was found to be 8.58 and 4.6 µg/ml for hydrochlorothiazide and candesartan cilexetil, respectively whereas the limit of detection, was found to be 2.8 and 1.5 µg /ml for hydrochlorothiazide and candesartan cilexetil, respectively. The % recovery range of candesartan cilexetil was 97.84-101.62% and 100.9-101.53% for hydrochlorothiazide. Variation in HPLC conditions (flow rate, column temperature, mobile phase composition, and wavelength) were used to evaluate the robustness of the method. The method proved to be robust and still produces good results.