Quantitative analysis of paracetamol polymorphs in powder mixtures by FT-Raman spectroscopy and PLS regression

The interplay between the paracetamol polymorphism and its molecular structures dissolved in supercritical CO2 in contact with the solid phase: In situ vibration spectroscopy and molecular dynamics simulation analysis

“…5), the first one was similar to that of the initially introduced polymorph I, whereas the second one contains spectral signatures of the presence of polymorph II. Indeed, six Raman spectral regions: 1500-1700 cm À1 , 1200-1260 cm À1 , 1000-1200 cm À1 , 700-900 cm À1 , 380-520 cm À1 , and 100-250 cm À1 are used in the literature as spectral signatures of the existence of paracetamol polymorph II (Al-Zoubi et al, 2002;Kachrimanis et al, 2007;Nanubolu and Burley, 2012;Szelagiewicz et al, 1999). In the case of IR-spectra (see Fig.…”

Simultaneous quantitative analysis of mebendazole polymorphs A–C in powder mixtures by DRIFTS spectroscopy and ANN modeling

“…Even when the crystal size of the mixture components is similar, the great differences in crystal morphology give rise to nonlinearities between the spectra and polymorphic content. Appropriate preprocessing and advanced multivariate calibration algorithm allow improved predictions when used in combination with spectroscopic techniques such as FTIR or FT-Raman [18,19]. Therefore, in the present study, in order to develop a simple method for the simultaneous quantitative analysis of mebendazole polymorphs in ternary powder mixtures, diffuse reflectance FTIR spectroscopy (DRIFTS) and spectral data preprocessing is combined with artificial neural network (ANN) modeling.…”

Effects of Moisture and Residual Solvent on the Phase Stability of Orthorhombic Paracetamol

“…The powder samples were packed into small aluminum cups and the spectra were recorded with 64 scans per spectrum over a range from 4,000 to 10 cm −1 at a resolution of 4 cm −1 . The monoclinic content of the crystals was determined applying a multivariate calibration method based on PLS regression, described in detail elsewhere (21). Additionally, the solventinduced transformation of form II was monitored with the same FT-Raman spectrometer at 25°C, using a 5 mm test tube.…”