Simultaneous UV-spectrophotometric method for the estimation of atenolol and amlodipine besylate in combined dosage form

Abstract

Simple, accurate, and precise UV-Spectrophotometric method was developed for the estimation of atenolol and amlodipine besylate in tablets. The standard stock solutions of atenolol and amlodipine besylate as well as mixed standard solution were diluted appropriately. The absorption spectra of the resultant solutions of atenolol and mixed standard solution were obtained by scanning between 264 to 308 nm against solvent blank. The spectra thus obtained was derivatised to obtain third order derivative [Dl (N) = 2] spectra. A tangent was drawn through the two satellite minima (DL 278.5 nm and DH ~286 nm). An altitude was drawn through this tangent to the inverted maxima termed as DB (~282 nm). The peak height was measured in mm and plotted against respective concentrations. The absorbances of the resultant solutions of amlodipine besylate as well as mixed standard solutions were read at 361 nm. A graph of concentration versus peak height in mm for atenolol was constructed. The E1cm value was calculated for amlodipine besylate at 361 nm. Atenolol was estimated in tablets by interpolation on the calibration curve. The concentration of amlodipine besylate in tablets was determined by E1cm. The proposed analytical method was found to be accurate, precise, and reproducible.