Autor: |
Daniel J. B. Hemming, Melissa J Larsen, Ray W. Wood, Robert G. Bergstrom, Lee D. Hansen |
Rok vydání: |
1997 |
Předmět: |
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Zdroj: |
International Journal of Pharmaceutics. 154:103-107 |
ISSN: |
0378-5173 |
DOI: |
10.1016/s0378-5173(97)00095-1 |
Popis: |
Lyophilized, amorphous acadesine crystallizes when exposed to water vapor. Isothermal calorimetry of samples held at constant humidity showed crystallization always occured within 1.5 h at relative humidities above about 50%, but was never observed at humidities below about 40%. The crystalline phase is anhydrous. Crystallization must proceed through an intermediate, metastable hydrate that immediately decomposes to the anhydrous crystal, a mechanism not commonly considered. The various possible mechanisms of water-catalyzed crystallization of amorphous materials can be distinguished by the dependence of the initiation time on the partial pressure of water vapor. |
Databáze: |
OpenAIRE |
Externí odkaz: |
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