Abstract

Interval partial least-squares calibration (iPLS) and synergical partial least-squares calibration (siPLS) methods in combination with near infrared spectroscopy coupled with integrating sphere (NIRA) have been developed for simultaneous determination of amlodipine (AML), valsartan (VAL) and hydrochlorothiazide (HCT) in raw material powder mixtures used for production commercial pharmaceutical product (tablets). Variable selection methods (iPLS and siPLS) were applied to select a spectral range that provided the lowest prediction error in comparison to the full-spectrum model. Spectral data were recorded between 10000 and 4000 cm-1 by NIRA and subdivided into 32 intervals. A relative standard error of prediction (RSEP) of 1.27% for VAL, 1.92% for HCT and 5.19% for AML was obtained after selection of better intervals by siPLS. Results shown that multivariate regression model associated to NIRA is a relatively simple, free-solvent and non-destructive procedure that could be applied to the simultaneous determination of AML, VAL and HCT in routine quality control of pharmaceuticals.

Key words: chemometrics, Exforge HCT®, pharmaceutical, quality control.