A new UV-spectrophotometric method for the simultaneous and separate estimation of Atenolol and amlodipine besylate in binary tablet formulations has been described. The method is based on the estimation of one drug in presence of another drug by absorbance method. In this method, two wavelengths 209 and 244.5 nm were selected for Atenolol and at these wavelengths the absorbance difference was found to be almost zero. Similarly, the two wavelengths 265 and 278 nm were selected for Amlodipine besylate and the absorbance difference was almost zero. In the mixture of Atenolol and amlodipine besylate solution the absorbance values of four wave lengths 209, 244.5, 265 and 278 nm were measured. The amount of Atenolol is directly proportional to the absorbance difference between 265 and 278 nm. Similarly, the amount of Amlodipine besylate is directly proportional to the absorbance difference between 209 and 244.5 nm.
