Poly(Ethylene) Glycol-Drug Eutectic Compositions: Complex Morphologies and Crystallization Kinetics

Hot-melt extruded drug loading in drug-polymer eutectic formulations of ibuprofen in polyethylene glycol (PEG) have been investigated. The crystallization rate and morphology of solid dispersion of the drugs were found to be depended on carrier molecular weight and its weight fraction. It was experimentally determined that PEG crystallization forms 2D spherulitic structures due to temperature gradient and rapid surface cooling. It was shown by NIR-Raman spectroscopy that the regime of cooling impacts an interaction between ibuprofen and PEG that was a cause for observed complex morphologies solidified melts. Observed phase separation in studied solid dispersions has been compared with the developed mathematical model of the crystallization process including rate of crystallization and spherulites' interaction.