Development and validation of LC method for simultaneous determination of two binary mixtures containing indapamide

A new sensitive, simple, rapid, and precise RP LC method with hydrochlorothiazide as internal standard has been developed for resolving two binary mixtures, perindopril with indapamide and captopril with indapamide, in pharmaceutical formulations. The drugs were separated at room temperature on a 250 mm x 4.6 mm, 5-mu m particle, cyanopropyl column with 10 mM KH(2)PO(4), pH 6.0-methanol 55:45 (v/v) as mobile phase at a flow rate of 1 mL min(-1). Detection was at 210 nm. Factors affecting the separation process were studied and optimized. The linearity, accuracy, and precision of the method were good, and the method was successfully applied to the determination of the two binary combinations in synthetic mixtures and commercial pharmaceutical products.