Chemometric Simultaneous Determination of Atorvastatin and Amlodipine in Tablets by PCR and PLS Calibrations

Principal component regression (PCR) and partial least squares (PLS) chemometric methods were applied to the simultaneous quantitative analysis of atorvastatin (ATO) and amlodipine (AML) in tablets without using a preliminary separation and even in presence of the overlapping spectra of the above mentioned compounds. For both PCR and PLS methods, a concentration set containing 17 different mixtures of ATO and AML in the linear concentration range of 0.0-20.0 mg/mL for both compounds was randomly prepared and then the absorbance values of the concentration set were measured at the 551 points-wavelength set with interval of Delta lambda=0.1 nm from 215 nm to 2 70 nm in the spectral range of 202320 nm. PCR and PLS calibrations were obtained by applying the PCR and PLS algorithms to the concentration set data (y-block) and their corresponding absorbance data (x-block). The validity of PCR and PLS chemometric methods was performed by using the independent synthetic mixtures and the standard addition technique. These analytical methods were applied to the commercial tablets and a good agreement was obtained between experimental results provided by the application of the PCR and PLS to the synthetic and real samples.