Development and Validation of Novel UV Methods for Irbesartan and Hydrochlorothiazide Combination

Simultaneous determination of Irbesartan (IRBE) and Hydrochlorothiazide (HTZ) in combined tablet dosage form has been developed by ratio spectra derivative and absorption correction spectrophotometry method. The amplitudes at 252.6 nm and 230 nm in the first derivative of the ratio spectra method were selected to determine IRBE and HTZ respectively and the second method was based on the absorption correction method in which IRBE and HTZ exhibit λ_max at 244 nm and 275.02 nm, respectively in 0.1 N HCL. HTZ has some interference due to IRBE at 275.02 nm, while HTZ do not show any absorption at 244 nm. The % assay for commercial formulations was found to be in the range 98.29-99.80 for IRBE and 98.91-100.10% for HTZ by the proposed methods, for both the formulations. Recovery was found in the range of 98.11-100.08% for IRBE and 98.54-99.29% for HTZ by ratio derivative method and 98.59-99.56% for IRBE and 99.33-100.12% for HTZ by absorbance correction method for both the Formulations. The methods were validated and found to be linear, precise and accurate, as per ICH guidelines. Absorbance correction method was applied for dissolution studies and drug release pattern was evaluated.