Spectrophotometric Methods for the Determination of Irbesartan in Pure and Pharmaceutical Dosage Forms

Two visible spectrophotometric methods have been developed for the determination of Irbesartan either in pure form or in their pharmaceutical formulations. The developed methods are based on reaction of naproxen with phenol red and bromocresol green. They are quantified spectrophotometrically at their absorption maximum at 422 nm (Method A) and 417nm (Method B). Beer's law was obeyed in the concentration ranges of 60–80 μg/ml and 120–160μg/ml respectively. The colors were found to be stable for more than 4 hours. The proposed methods were successfully applied for determination of the naproxen in their pharmaceutical formulations and the results compared favorably to that of reference methods, hence are recommended for quality control and routine analysis.