Chemometric Simultaneous Determination of Atorvastatin and Amlodipine in Bulk and Tablets

Abstract

A simple, accurate and precise UV-spectrophotometric method based inverse least-squares was developed for the simultaneous determination of atorvastatin and amlodipine in tablet formulation. The absorbance values of the two analytes were linear with the concentration at the wavelengths taken at 5 nm interval over the range of 230 -260 nm. The calibration equations were developed using the absorbance values of nine synthetic mixtures containing different concentrations of two analytes measured at 5 nm intervalsin the range of 230 -260 nm. The developed equations werethen validated by calculating the analytes recovery from the analysis of a set of another five synthetic mixtures, the mean% recoveries were 100.02% and 100.06% with the corresponding% RSD of ±0.36 and±0.51 for atorvastatin and amlodipine, respectively. The calibration equations obtained were then used to obtain the concentration of each analyte in commercial samples. The mean % recoveries were 100.43% and 100.28% with the corresponding% RSD of ±0.78 and±0.85 for atorvastatin and amlodipine, respectively. The validity of the proposed method was confirmed through the statistical comparison of the obtained results with those obtained by a reference method utilizing high performance liquid chromatography for the determination of the two actives, the calculated t-values at (P=0.05, n =6) were 1.47 and 0.73 compared to the tabulated value of 2.23.