Abstract
Thiamine hydrochloride (THCl) can exist as an anhydrate (AH) and as a hemihydrate (HH). AH sorbs water as a function of environmental water vapor pressure to form a nonstoichiometric hydrate (NSH). NSH dehydration is initiated at ∼408C to yield AH, an isomorphic desolvate (ID) of NSH (Chakravaty et al., 2009, J Pharm Sci). Upon heating, dehydration of HH occurs only at elevated temperatures (>12°8C) and is accompanied by chemical decomposition. When heated at reduced temperature (60-90°C) and pressure (20-760 mTorr), HH was incompletely dehydrated with partial loss of long-range lattice order. Complete dehydration of HH to AH was achieved through a solvent-mediated transformation in ethanol. The crystal structures of NSH and HH exhibit pronounced differences in the hydrogen bonding of water. The dehydration mechanism of NSH and HH can be explained by the "continuous and unified" dehydration model. 10
Original language | English (US) |
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Pages (from-to) | 1882-1895 |
Number of pages | 14 |
Journal | Journal of Pharmaceutical Sciences |
Volume | 99 |
Issue number | 4 |
DOIs | |
State | Published - Apr 2010 |
Bibliographical note
Funding Information:The assistance of Mr. Gilbert Alhstrand (Imaging center, College of Biological Sciences, University of Minnesota) with the cryo‐SEM is gratefully acknowledged. Partial financial support was received from Dane O. Kildsig Center for Pharmaceutical Processing Research. Paroma Chakravarty is the recipient of the Doctoral Dissertation Fellowship from the Graduate School, University of Minnesota. Part of this work was carried out in the I.T. Characterization facility of the University of Minnesota which receives partial support from NSF through the NNIN program.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
Keywords
- Crystal structure
- Dehydration
- Hydrates
- Solid-state NMR
- Spectroscopy
- X-ray powder diffractometry