Small and wide angle high energy x-ray scattering experiments were performed upon cooling itraconazole from the melt to investigate the structural origin of the two transitions at ~74 o C and ~90 o C observed in DSC measurements. Slight changes to the main WAXS peak at Q=1.33±0.01 Å -1 were observed at 90 o C and are found to be inter-molecular in nature, suggesting an isotropic liquid to isotropic transition. This finding was supported by complementary wide angle neutron scattering measurements. For temperatures at and below ~74 o C two strong rings appear in the 2D-SAXS pattern at Q=0.24±0.01 Å -1 and 0.43±0.01 Å -1 . The SAXS spectra were further deconvoluted into sharp and broad components. A narrowing of the broad component is associated with only minor changes in the packing arrangements of the itraconazole molecules below ~90 o C, while the appearance of the sharp component below ~74 o C is attributed to the formation of a polydomain lamellar phase.
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