Antisolvent Crystallization of the Polymorphs of l -Histidine as a Function of Supersaturation Ratio and of Solvent Composition
| Autor: | Joop H. ter Horst, C. P. Mark Roelands, and Herman J. M. Kramer, Shanfeng Jiang, PJ Jansens, Mitsutaka Kitamura |
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| Rok vydání: | 2006 |
| Předmět: | |
| Zdroj: | Crystal Growth & Design. 6:955-963 |
| ISSN: | 1528-7505 1528-7483 |
| DOI: | 10.1021/cg050529d |
| Popis: | During the antisolvent crystallization of l-histidine from aqueous solution with the antisolvent ethanol, the polymorphic fraction of the metastable polymorph B increased with increasing supersaturation ratio. For supersaturation ratio SA ≤ 2.0, a mixture of the stable polymorph A and the metastable polymorph B was obtained, while for high supersaturation, SA ≥ 2.3, only form B was observed. The supersaturation ratio was increased either by increasing the l-histidine concentration in the aqueous solution or by increasing the ethanol volume fraction. The induction time for the antisolvent crystallization was one to several orders of magnitude smaller than the time to transform the metastable polymorph B into stable polymorph A in solution, indicating that both polymorphs formed simultaneously. Process simulation of the batch antisolvent crystallization of the polymorphs of l-histidine was applied to predict the outcome of the competition between heterogeneous nucleation and polynuclear growth rates for bot... |
| Databáze: | OpenAIRE |
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