著者

北岡 宏章 和田 千佐 諸井 黎明 伯水 英夫

出版者

The Pharmaceutical Society of Japan

雑誌

Chemical and Pharmaceutical Bulletin (ISSN:00092363)

巻号頁・発行日

vol.43, no.4, pp.649-653, 1995-04-15 (Released:2008-03-31)

参考文献数

6

被引用文献数

16 35

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Differential scanning calorimetry (DSC) curves of levofloxacin hemihydrate measured under various conditions showed different thermograms. These phenomena were attributed to be the dehydration. Dehydration caused a multiple-phase transition. Dehydration at a higher temperature (above 70°C) gave a sharp endothermic peak on the DSC curve due to the melting of the γ form, and at a lower temperature (below 50°C) gave a sharp endothermic peak due to the melting of the α form.In contrast, the thermal behavior of levofloxacin monohydrate was not affected by dehydration. The difference in the thermal behavior between the hemihydrate and the monohydrate might be attributed to a difference in the interaction between levofloxacin and crystal water. Observations by thermomicroscopy, the changes in powder X-ray diffraction patterns during heating, and single X-ray analysis all supported the above interpretation.