Crystallization of supercooled fenofibrate studied at ambient and elevated pressures

Abstract

In this work, we have performed a detailed investigation on the crystallization tendency of the modeled glass-forming pharmaceutical compound, fenofibrate. To do this, we have employed four different experimental techniques allowing following of the crystallization process. This has included dielectric spectroscopy, optical microscopy, X-ray diffraction and differential scanning calorimetry. From the crystallization kinetic studies carried out at atmospheric pressure, we have determined the temperature dependence of the crystal growth rate and the overall crystallization rate. It was found that the time scale of the molecular motions responsible for α-relaxation correlates much better with the crystal growth rate than with the overall crystallization rate. Experiments carried out under varying thermodynamic conditions while remaining on the same timescale of α-relaxation have demonstrated that the crystallization tendency of the supercooled fenofibrate significantly slows down with increasing pressure. Lastly, we have also shown that the thermodynamic history of reaching crystallization conditions has a substantial impact on its overall progress.