ANALYTICAL METHOD DEVELOPMENT AND VALIDATION FOR THE ESTIMATION OF CANDESARTAN BY DERIVATIVE SPECTROSCOPY (FIRST ORDER AND SECOND ORDER)

Candesartan cilexetil, a prodrug is a racemic mixture containing one chiral center at the cyclohexyloxy-carbonyloxy- ethyl ester group. It is soluble in dimethyl formamide, acetone, methanol, 0.1 N sodium hydroxide solution and insoluble in water. Objective of the present study is to develop a simple, sensitive, accurate, precise and rapid derivative spectrophotometric method for the estimation of candesartan in pure form. For the estimation of candesartan, solvent system employed was absolute methanol and wavelength of detection (λ_det) was 268.8 nm for first order derivative spectroscopy. The linearity was obtained in the range 10 – 20µg/ml. The limit of detection is 0.5µg/ml and limit of quantification was fund to be 1.63µg/ml. For the estimation of candesartan, solvent system employed was absolute methanol and wavelength of detection (λ_det) was 284.3 nm for second order derivative spectroscopy. The linearity was obtained in the range 40 – 160 µg/ml. The limit of detection is 6.7 µg/ml and limit of quantification was fund to be 20.4 µg/ml. Obtained results showed that there is minimum intra day and inter day variation. Both the developed methods were validated and recovery studies were also carried out. Sample recovery using the above methods 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 and second order derivative spectroscopy methods are simple, rapid and reproducible and further it can be used for the analysis.