Characterization of Non-stoichiometric Hydration and the Dehydration Behavior of Sitafloxacin Hydrate
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- Suzuki Tetsuya
- Analytical & Quality Evaluation Research Laboratories, Pharmaceutical Technology Division, Daiichi Sankyo Co., Ltd. Department of Pharmaceutics, School of Pharmaceutical Sciences, Toho University
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- Araki Tetsuya
- Analytical & Quality Evaluation Research Laboratories, Pharmaceutical Technology Division, Daiichi Sankyo Co., Ltd.
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- Kitaoka Hiroaki
- Analytical Group II, Research Department II, Daiichi Sankyo RD Associe Co., Ltd.
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- Terada Katsuhide
- Department of Pharmaceutics, School of Pharmaceutical Sciences, Toho University
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Description
Sitafloxacin (STFX) hydrate is a non-stoichiometric hydrate. The hydration state of STFX hydrate varies non-stoichiometrically depending on the relative humidity and temperature, though X-ray powder diffraction (XRPD) of STFX hydrate was not affected by storing at low and high relative humidities. The detailed properties of crystalline water of STFX hydrate were estimated in terms of hygroscopicity, thermal analysis combined with X-ray powder diffractometry, crystallography and density functional theory (DFT) calculation. STFX hydrate changed the water contents continuously and reversibly from an equivalent amount of dihydrate through that of sesquihydrate depending on the relative humidity at 25°C. Thermal analysis and X-ray powder diffraction (XRPD) simultaneous measurement also revealed that STFX hydrate dehydrated into a hydrated state equivalent to monohydrate by heating up to 100°C, whereas XRPD patterns were slightly affected. This indicated that the crystal structure of STFX hydrate was retained at the dehydration level of monohydrate. Single-crystal X-ray structural analysis showed that two STFX molecules and four water molecule sites were contained in an asymmetric unit. STFX molecules formed a channel structure where water molecules were included. At the partially dehydrated state, at least two of four water molecules were considered to be disordered in occupancy and/or coordinates. Insight into the crystal structure of STFX hydrate stored at low and high relative humidities and geometry of the hydrogen bond were helpful to estimate the origin of non-stoichiometric hydration of STFX hydrate.
Journal
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- Chemical and Pharmaceutical Bulletin
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Chemical and Pharmaceutical Bulletin 60 (1), 45-55, 2012
The Pharmaceutical Society of Japan
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Keywords
Details 詳細情報について
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- CRID
- 1390282679153829120
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- NII Article ID
- 130001852347
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- NII Book ID
- AA00602100
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- ISSN
- 13475223
- 00092363
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- NDL BIB ID
- 024029705
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- Text Lang
- en
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- Data Source
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- JaLC
- NDL
- Crossref
- CiNii Articles
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- Abstract License Flag
- Disallowed