ABSTRACT

The aim of this study was to develop a reversed-phase high performance liquid chromatographic (RPHPLC) method for the simultaneous determination of quinapril (QNP) and hydrochlorothiazide (HCZ) in pharmaceutical dosage forms. In this method quinapril, hydrochlorothiazide and perindopril (internal standard) were separated using a reversed phase column (Hichrom C18; 250×4.6 mm i.d.; 10 µm) with acetonitrile: potassium dihydrogen phosphate (at pH 2.5; 0.067 M) (40:60 v/v) as a mobile phase. UV visible dedector set at 211 nm and mobile phase was pum-ped at 1.0 mL/min flow rate. The chromatographic separation was performed at 25 oC. In these conditions the re-tention times for quinapril, hydrochlorothiazide and perindoprile were 4.391, 3.237 and 3.931 min, respectively. Linearity was obtained in the concentration range of 2-30 µg/mL for quinapril and 1.25-18.75 µg/mL for hydrochlo-rothiazide. The proposed method has been fully validated and allows a number of cost- and time-saving benefits. It was successfully applied to the determination of QNP and HCZ in synthetic mixtures and in pharmaceutical dosa-ge forms. The proposed method is simple, rapid and suitable for quality control (QC) applications.