Simultaneous Determination of Irbesartan and Hydrochlorothiazide in Tablets by Derivative Spectrophotometry

Abstract A second-derivative spectrophotometric method for the simultaneous determination of irbesartan (IRB) and hydrochlorothiazide (HCT) in tablets is described. Measurements were made at the zero-crossing wavelengths at 230.1 nm for IRB and 232.7 nm for HCT. The calibration graphs were linear in the range of 14.4–33.6 mg L−1 for IRB and 1.2–2.8 mg L−1 for HCT. The limits of quantitation were 5.0 and 1.1 mg L−1. The proposed method was successfully applied to the simultaneous determination of IRB and HCT in commercial tablets with a high percentage of recovery, good accuracy, and precision.