Liquid Chromatographic Separation and Analysis of Telmisartan and Hydrochlorothiazide in Pharmaceutical Formulations

An accurate, simple and precise RP-HPLC method for the simultaneous determination of telmisartan and hydrochlorothiazide in pharmaceutical formulations was developed and validated. Chromatographic separation of two drugs was achieved on a Kromasil C18, (250x4.6nm, 5μm) column by using the mobile phase consisted of methanol, tetrahydrofuran and water in the ratio 55:05:40 at a flow rate of 1mL/min and the wavelength of detection was at 234 nm. The retention time for telmisartan and hydrochlorothiazide were found to be 2.3 and 3.8 min respectively. The linearity of the developed method was tested over a concentration range of 50-100 μg/mL and the correlation coefficient (r 2 ) of regression was 0.999 which is almost equal to 1. The limit of quantification was 0.5μg/mL for telmisartan and 0.4μg/mL for hydrochlorothiazide and the limit of detection was 0.1μg/mL for both telmisartan and hydrochlorothiazide. The mean percentage recoveries were 99.2% for telmisartan and 99.8% for hydrochlorothiazide respectively. INTRODUCTION: Telmisartan (TEL), (fig1) a non-peptide molecule and its IUPAC name is 4 ׳ [(1,4 ׳ -dimethyl-2 ׳ -propyl [2,6 ׳ -bi-1Hbenzimidazol]-1 ׳ -yl) methyl] [1,1 ׳ -biphenyl]-2carboxylic acid 1 . It is an angiotensin II, type I blocker and is used as an antihypertensive along with hydrochlorithiazide.