A SAXS-WAXS study of the endothermic transitions in amorphous or supercooled liquid itraconazole
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 °C and ~90 °C observed in DSC measurements. Slight changes to the main WAXS peak at Q = 1.33 ± 0.01 Å –1 were observed at 90 °C and are found to be inter-molecular in nature, suggesting a liquid to isotropic transition. This finding was supported by complementary wide angle neutron scattering measurements. For temperatures at and below ~74 °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. Lastly, a narrowing of the broad component is associated with only minor changes in the packing arrangements of the itraconazole molecules below ~90 °C, while the appearance of the sharp component below ~74 °C is attributed to the formation of a polydomain lamellar phase.
- Authors:
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[1]
; [2]
; [3]
; [4]
; [5]
; [4]
; [6]
; [2]
- Argonne National Lab. (ANL), Argonne, IL (United States); Arizona State Univ., Tempe, AZ (United States)
- Arizona State Univ., Tempe, AZ (United States)
- Univ. of Sheffield, Sheffield (United Kingdom)
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Purdue Univ., West Lafayette, IN (United States)
- Publication Date:
- Grant/Contract Number:
- AC05-00OR22725; AC02-06CH11357; AC02-06CH1135
- Type:
- Accepted Manuscript
- Journal Name:
- Thermochimica Acta
- Additional Journal Information:
- Journal Volume: 644; Journal Issue: C; Journal ID: ISSN 0040-6031
- Publisher:
- Elsevier
- Research Org:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS); Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Org:
- USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 36 MATERIALS SCIENCE
- OSTI Identifier:
- 1329117
- Alternate Identifier(s):
- OSTI ID: 1364641; OSTI ID: 1396821
- Free Publicly Accessible Full Text
- Accepted Manuscript (Publisher)
-
Accepted Manuscript (DOE)
- Publisher's Version of Record
- https://doi.org/10.1016/j.tca.2016.10.004