Abstract

Two simple and rapid ultraviolet spectrophotometric methods were developed to estimate indapamide and atenolol in marketed tablet formulation. These ultraviolet methods are simple, economical and less time consuming as compared to other instrumental methods. The developed methods included the simultaneous equations method and absorbance ratio method. Methanol was used as a dissolving solvent and distilled water was used as a diluent. For the simultaneous equations method, the wavelengths selected were 241 nm (λ_max of indapamide) and 224.4 nm (λ_max of atenolol) and for absorbance ratio method, the two wavelengths selected were 233.8 nm (isosbestic point) and 224.4 nm (λ_max of atenolol). In both approaches, the linearity was proven over concentration ranges of 2-20 µg/ml for indapamide and 10-80 µg/ml for atenolol. The percentage purity in the marketed formulation was found to be 99.79 % for indapamide and 98.57 % for atenolol by simultaneous equations method and 99.56 % for indapamide and 100.0 % for atenolol by absorbance ratio method, which lies within the acceptance criteria i.e., 95 %-105 %. The methods were validated as per the International Council for Harmonisation guidelines and were found to be linear, precise, accurate, sensitive and robust and hence can be used for the estimation of indapamide and atenolol simultaneously in tablet formulation.