Determination of captopril in pharmaceutical preparation and biological fluids using two- and three-way chemometrics methods

Spectrophotometric method has been developed for the direct quantitative determination of captopril in pharmaceutical preparation and biological fluids (human plasma and urine) samples. The method was accomplished based on parallel factor analysis (PARAFAC) and partial least squares (PLS). The study was carried out in the pH range from 2.0 to 12.8 and with a concentration from 0.70 to 61.50 μg mL−1 of captopril. Multivariate calibration models such as PLS at various pH and PARAFAC were elaborated from ultraviolet spectra deconvolution and captopril determination. The best models for this system were obtained with PARAFAC and PLS at pH 2.0. The applications of the method for determination of real samples were evaluated by analysis of captopril in pharmaceutical preparations and biological fluids with satisfactory results. The accuracy of the method, evaluated through the RMSEP, was 0.5801 for captopril with best calibration curve by PARAFAC and 0.6168 for captopril with PLS at pH 2.0 model.