The hemitartrate salt of a compound represented by the following structural formula: (Formula I Hemitartrate), which may be used in pharmaceutical applications, are disclosed. Particular single crystalline forms of the Formula (I) Hemitartrate are characterized by a variety of properties and physical measurements. As well, methods of producing crystalline Formula (I) Hemitartrate, and using it to inhibit glucosylceramide synthase or lowering glycosphingolipid concentrations in subjects to treat a number of diseases, are also discussed. Pharmaceutical compositions are also described.揭露由下述結構分子式所表示的化合物的半酒石酸鹽：(分子式I半酒石酸鹽)，其可用於藥學應用。該分子式(I)半酒石酸鹽之特定單一結晶形式的特徵在於各種特性以及物理測量。同時，也討論了製造結晶分子式(I)半酒石酸鹽，以及使用它以抑制個體中葡萄糖神經醯胺合成酶或降低醣神經鞘脂濃度，以治療許多疾病的方法。也描述了藥學組成物。
