Hydrophilic interaction chromatography‐tandem mass spectrometric analysis of irbesartan in human plasma: Application to pharmacokinetic study of irbesartan

A hydrophilic interaction chromatography‐tandem mass spectrometric method (HILIC/MS/MS) for the determination of irbesartan in human plasma was developed. Irbesartan and losartan (internal standard) were extracted from human plasma with ethyl acetate at acidic pH. The analytes were analyzed on a Luna HILIC column with the mobile phase of ACN–ammonium formate (50 mM, pH 6.5) (96:4, v/v) and detected by ESI MS/MS in the selected reaction monitoring mode. The standard curve was linear (r² = 0.9981) over the concentration range of 10–2500 ng/mL and the lower LOQ was 10 ng/mL using 100 μL of plasma sample. The CV and relative error for intra‐ and interassay at four QC levels were 2.9 to 8.1% and –2.7 to 2.3%, respectively. There were less absolute and relative matrix effects for irbesartan and losartan. The present method was successfully applied to the pharmacokinetic study of irbesartan after oral dose of irbesartan (150 mg tablet) to male healthy volunteers.