The present invention relates to a pharmaceutical composition for treating or
preventing obesity, comprising novel crystalline sibutramine methanesulfonate hemihydrate
of formula (I). The crystalline sibutramine methanesulfonate hemihydrate according
to the present invention has a much higher solubility in water, and enhanced stability
under a high humidity/temperature condition, as compared with sibutramine hydrochloride
monohydrate
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