Simultaneous HPLC–UV analysis of telmisartan and hydrochlorothiazide in human plasma

A specific, sensitive and rapid method based on high performance liquid chromatography (HPLC) was developed for the simultaneous determination of telmisartan (TELM) and hydrochlorothiazide (HCT) in human plasma using indapamide as internal standard. The method utilizes proteins precipitation with acetonitrile as only sample preparation prior to RP-HPLC. The analytes were chromatographed on shim-pack cyanopropyl column in isocratic elution with methanol: 10 mM ammonium acetate solution (pH 6.0) (35:65 v/v) as mobile phase at a flow rate of 1 ml/min and the wavelength of detection was 270 nm. The method was validated over the concentration range of 1–10 μg ml^-1 for TELM and 0.31– 3.12 μg ml^-1 for HCT in human plasma. Inter- and intra-run precision of TELM and HCT were less than 3.60% and the accuracy was less than 1.868%. The linearity, recovery, matrix effect and stability were validated for TELM/HCT in human plasma.