Crystalline Polymorphism and Molecular Structure of Sodium Pravastatin
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- 作者：A. P. Martí ; n-Islá ; n ; M. C. Cruzado ; R. Asensio ; C. Ignacio Sainz-Dí ; az
- 刊名：Journal of Physical Chemistry B
- 出版年：2006
- 出版时间：December 28, 2006
- 年：2006
- 卷：110
- 期：51
- 页码：26148 - 26159
- 全文大小：389K
- 年卷期：v.110,no.51(December 28, 2006)
- ISSN：1520-5207
文摘
In this work different crystallization processes of sodium pravastatin are explored and a new polymorph isobtained. The analytical results of powder X-ray diffraction (PXRD) and thermal analysis for this newpolymorph indicate that it is different from the polymorphs previously reported. This new crystal form showsdifferent physical-chemical properties than the previous forms, such as crystallographic structure, thermalbehavior, and melting point, 181.5 
C. Besides, all crystallization processes previously reported use an aproticsolvent as antisolvent. However, we propose a new crystallization process for sodium pravastatin that usesonly protic solvents, overcoming industrial scaling and environmental problems. Variable-temperature PXRDexperiments show a transformation between different crystal forms in the range of 80-120 C. Solid-state13C NMR, reported in this work for the first time, and Fourier transform infrared (FT-IR) studies of somepolymorphs show some differences in intermolecular interactions, especially with carboxylate and hydroxylgroups. Quantum mechanical calculations of the pravastatin molecule are also presented for the first time,obtaining a molecular structure similar to the experimental structure existing within the crystal lattice of thetert-octylamonium salt of pravastatin.
C. Besides, all crystallization processes previously reported use an aproticsolvent as antisolvent. However, we propose a new crystallization process for sodium pravastatin that usesonly protic solvents, overcoming industrial scaling and environmental problems. Variable-temperature PXRDexperiments show a transformation between different crystal forms in the range of 80-120 C. Solid-state13C NMR, reported in this work for the first time, and Fourier transform infrared (FT-IR) studies of somepolymorphs show some differences in intermolecular interactions, especially with carboxylate and hydroxylgroups. Quantum mechanical calculations of the pravastatin molecule are also presented for the first time,obtaining a molecular structure similar to the experimental structure existing within the crystal lattice of thetert-octylamonium salt of pravastatin.