Development and Validation of Spctrophotometric Method for Simultaneous Estimation of Amlodipine Besylate and Indapamide in Tablet Dosage Form

The present manuscript describes simple, sensitive, rapid, accurate, precise and economic dual wavelength spectrophotometric method for simultaneous determination of amlodipine besylate and indapamide in combined tablet dosage form. The utility of dual wavelength data processing program is its ability to calculate unknown concentration of components of interest in a mixture containing an interfering component. The principle for dual wavelength method is “the absorbance difference between two points on the mixture spectra is directly proportional to the concentration of the component of interest”. The wavelengths selected for determination of amlodipine besylate were 255 nm and 360 nm, whereas the wavelengths selected for determination of indapamide were 241.6 nm and 217.6 nm. The two drugs follow Beer-Lambert's law over the concentration range of 10–60 μg/ml for AMLO and 3–18 μg/ml for INDA. The method was successfully applied to pharmaceutical dosage form because no interference from the tablet excipients was found. The results of analysis have been validated statistically and by recovery studies.