Mass Spectroscopy

Triamterene is a potassium-sparing diuretic which is commonly used in combination with Hydrochlorothiazide, a thiazide-type diuretic in clinical management of edema and moderate hypertension. In this study, a rapid and sensitive LC–MS/MS method was developed and validated for determination of Triamterene and Hydrochlorothiazide from K3EDTA based Human Plasma. Triamterene D5 and Hydrochlorothiazide 13C6 were used as an Internal Standards for analysis of Plasma Samples.  The analytes and internal standards, were extracted by liquid–liquid extraction method using Se Quant®ZIC-HILIC, (5um,200A 150 X 4.6 mm)  column with Acetonitrile and 2 mM Ammonium formate containing 0.1% formic acid (80:20 v/v) as the mobile phase. Linearity was assessed from 3.10ng/mL to 229.72 ng/mL for Triamterene and 5.47 ng/mL to 405.27 ng/mL for Hydrochlorothiazide in plasma.  No significant matrix effects were observed by analysing the plasma samples on LC–MS/MS. The accuracy was in the range of 98.32 % to 102.86 % for both compounds. Triamterene and Hydrochlorothiazide were found to be stable up to 120 days in K3EDTA based Human Plasma at -20ºC. The stability of Triamterene and Hydrochlorothiazide in plasma was confirmed up to five freeze-thaw cycles (−20°C) and on bench up to 25 hours. The proposed bioanalytical method for the quantitation of Triamterene and Hydrochlorothiazide from K3EDTA based human plasma samples was satisfactorily validated. It can be used to include study data for quantitation of Triamterene and Hydrochlorothiazide from K3EDTA based human plasma in bioequivalence and bioavailability study.