Development of an analytical method for Irbesartan and Hydrochlorothiazide in human plasma

Abstract

    This paper presents the process of developing and partially validating the analytical procedure for irbesartan (IRB) and hydrochlorothiazide (HCTZ) in human plasma via the LC-MS/MS technique. The analytical method used telmisartan as an internal standard for the determination of irbesartan and hydrochlorothiazide. The analytes and internal standards were extracted using liquid-liquid extraction technique with tert-butyl methyl ether, Gemini C18 column (150 mm × 2 mm; 3 µm), Methanol mobile phase – ammoniumformat buffer at 5 mM, pH = 5 (80:20), flow rate 0.4 mL/min, and sample injection volume 2 µL. Irbesartan and telmisartan were analyzed in the positive ionization mode and hydrochlorothiazide in the negative ionization mode. According to the US-FDA and EMA guidelines for the validation of drug analytical methods in biological fluids, the results of partial validation of the analytical procedure showed that the procedure achieved specificity, extraction efficiency of more than 95 %, and linearity over the intended concentration ranges, and achieving intraday and intraday accuracy and precision, with the lower limits of quantification for IRB and HCTZ being 0.005 µg/mL and 0.901 ng/mL, respectively.