STABILITY INDICATING ASSAY AND ESTIMATION OF IRBESARTAN BY FIRST ORDER UV DERIVATIVE SPECTROPHOTOMETRY

Introduction: Irbesartan is chemically 2-butyl-3-({4-[2-(2H-1,2,3,4-tetrazol-5-yl) phenyl] phenyl} methyl) -1,3-diazaspiro [4.4] non-1-en-4-one. Irbesartan is an Angiotensin II receptor antagonist effective in the treatment of Hypertension.  It is also effective in the treatment of High blood pressure.  It is also effective when used alone or in combination with other drugs. Aims and Objectives: Objective of the present study is to develop a simple, sensitive, accurate, precise and rapid first order derivative spectrophotometric method for the estimation of irbesartan in pure form. Results: For the estimation of irbesartan, solvent system employed was 50% v/v aqueous ethanol and wavelength of detection (λ_det) was 237 nm. The linearity was obtained in the range 8 -18 µg/ml, with a regression coefficient, R₂ = 1. Discussion: Obtained results showed that there is minimum intraday and inter day variation. The developed method was validated and recovery studies were also carried out. Sample recovery using the above method was in good agreement with their respective labeled claims, thus suggesting the validity of the method and non-interference of formulation excipients in the estimation. First order derivative spectroscopy method is simple, rapid and reproducible and further it can be used for the analysis.