QUALITATIVE DISCRIMINATION BETWEEN PARACETAMOL TABLETS MADE BY NEAR INFRARED SPECTROSCOPY AND CHEMOMETRICS WITH REGARD TO POLYMORPHISM

Polymorphism is an important characteristic of pharmaceutical products because different polymorphs exhibit different physicochemical stabilities, dissolution rates, etc., which makes them different in therapeutic efficiency. Thus, it is important to control the polymorphic struc-ture of pharmaceutical products. A spectroscopy method based on Fourier transform near in-frared (FT-NIR) spectroscopy and chemometric techniques is introduced to classify paraceta-mol preparations according to polymorphic changes. X-ray diffraction (XRD) and FT-NIR studies were carried out on standard samples, paracetamol preparations (acetaminophen tablet), and also the additives. A direct comparison was performed between the spectroscopic data and those obtained by XRD. The NIR and XRD analyses of paracetamol preparations show some distinct differences, particularly in the Iranian tablet. These differences are found to be related to polymorphism and paracetamol purity. The cluster analysis (CA) and principal component analysis (PCA) were utilized to classify the paracetamol preparations. FT-NIR spectroscopy provides a simple, rapid and accurate qualitative analysis method for the identification of paracetamol polymorphs. K e y w o r d s: paracetamol, classification, polymorphism, chemometrics, Fourier transform