The use of through vial impedance spectroscopy (TVIS) for determination of ice nucleation, solidification end point, and mannitol crystallization during freezing and re-heating. Poster presentation at the APS PharmSci Conference Greenwish, 11-13th Sept. 2019
De Montfort University, 2019
Online
unknown
Zugriff:
This is a study of the freezing/reheating behavior of aqueous solutions of mannitol with respect to lyophilization process development given the prevalent use of the excipient. Here, through-vial impedance spectroscopy (TVIS) was used to study the thermophysical kinetics of an aqueous solution of 5%w/v mannitol during a freezing and re-heating phase of a freeze-drying cycle. Temperature calibration of the TVIS parameter FPEAK enabled the determination of the ice nucleation temperature Tn at −13 oC while the ice solidification end point was observed based on the time profile of C' (0.2MHz), i.e. the real part capacitance at 0.2 MHz. A time difference of 20 min between the onset and end point then defines the ice solidification time ti. A later step in C' (0.2MHz) indicated that mannitol crystallized at -32 oC and 20 minutes from end of ice solidification. Upon reheating at 0.2 oC/min, a large increase in C' (0.2MHz) was seen at −32 oC indicating the onset of melting of mannitol crystals which then lasted 20 min.
Titel: |
The use of through vial impedance spectroscopy (TVIS) for determination of ice nucleation, solidification end point, and mannitol crystallization during freezing and re-heating. Poster presentation at the APS PharmSci Conference Greenwish, 11-13th Sept. 2019
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Autor/in / Beteiligte Person: | Ogugua, Longinus ; Smith, Geoff ; Orun, Ahmet |
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Veröffentlichung: | De Montfort University, 2019 |
Medientyp: | unknown |
DOI: | 10.21253/dmu.9867764.v1 |
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