Patent 7138140 was granted and assigned to Taiho Pharmaceutical on November, 2006 by the United States Patent and Trademark Office.
Provided are a suplatast tosilate crystal showing characteristic peaks in powder X-ray diffraction diffraction angles (20±0.1°) of 5.6°, 9.0°, 11.0°, 15.3°, 16.5°, 17.2°, 17.9°, 19.2°, 19.9°, and 21.5°; and a preparation process of the crystal. Owing to merits such as fluctuation-free optically active substance ratio, low hygroscopicity and high storage stability, the suplatast tosilate crystal of the present invention can be mass-produced easily and, at the same time, is advantageous in drug preparation quality management. It is thus excellent as raw material for pharmaceuticals.