Application of multivariate curve resolution to in situ THz - Raman spectroscopy of amorphous solid dispersions in pharmaceutical products

Off-line techniques such as differential scanning calorimetry (DSC) can be used to characterize solidified extrudates from a hot-melt extrusion (HME) process. However, off-line measurements are not representative of the melt mixture in the HME barrel. THz-Raman spectroscopy can be used to monitor solid dispersions of the melt mixture in situ. To avoid needing off-line reference measurements, calibration-free methods for spectral analysis are advantageous. Multivariate curve resolution (MCR) is a calibration-free method of resolving mixture spectra into pure component contributions using an iterative optimization within a set of constraints. The outputs are pure component spectra and concentration profiles for each component.