Development and Validation of Ratio Spectra Derivative Spectrophotometric Method for Determination of Ternary Mixture of Aspirin, Atenolol and Amlodipine Besylate in Formulation

A simple, economical, precise and accurate ratio spectra derivative spectrophotometric method for Aspirin (ASP), Atenolol (ATN), and Amlodipine besylate (AML) ternary combination on laboratory prepared tablet formulation has been developed. The method is based on obtaining first derivative of ratio spectra and measuring amplitude at selected wavelength. The derivative amplitudes at 312.5 nm, 315.5 nm and 347.0 nm were selected for measuring the response of Aspirin (ASP), Atenolol (ATN), and Amlodipine besylate (AML), respectively. Beer’s law is obeyed in the concentration range of 20-100 μg ml^-1 for ASP and 10-50 μg ml^-1 for ATN and 1-5 μg ml^-1 AML. The % assay was found to be in the range 98.0-101.0% for ASP and 98.91-101.72% for ATN and 98.71-101.2% for AML by the proposed method. The method was validated with respect to linearity, precision and accuracy. Recovery was found in the range of 98.72-100.64% for ASP and 98.45-101.21% for ATN and 98.32-101.12% for AML.