Development of spectrophotometric method to assay irbesartan in pure and in pharmaceutical dosage form using diazotization reaction

Abstract

This study includes the development of an accurate and cost-effective spectrophotometric method for the determination of irbesartan in pure form and in its formulation dosages. In this strategy, m-Aminophenol reagent was displaced with an excess amount of sodium nitrite in an acidic medium and the resulting diazonium salt followed by cupling with irbesartan in the base arrangement of NaOH to create a water-soluble yellow azo dye has maximum absorption at 444 nm versus reagent blank. Under optimum conditions, the linearity of the method obeyed Beer's law in the concentration range 1- 8 μg/ml with an excellent determination coefficient(R2= 0.9993) and molar absorptivity 9.856 ×104 l/mol.cm. and sandell's sensitivity index value equal to 0.00434μg/cm2 .The detection limit (LOD) and quantification limit (LOQ) have also been estimated and their values were found to be 0.452 and 0.876 μg/ ml , respectively. A relative error% was calculated and found in the range -0.5% to 2.64% , while the precision (RSD) was estimated as ≤ 2.17%. The stoichiometry of the resulting azo dye was found to be 1:1 irbesartan : m-aminophenol. The suggested procedure was applied to the analysis of irbesartan in tablets.