Ushio T, Endo K, Yamamoto K
Saitama Factory, Taiho Pharmaceutical Co., Ltd., Japan.
Yakugaku Zasshi. 1996 Nov;116(11):866-75. doi: 10.1248/yakushi1947.116.11_866.
The physicochemical properties of the enantiomer and racemates of suplatast tosilate (ST) were investigated by means of infrared spectroscopy, solid-state 13C CP/MAS NMR spectroscopy, thermal analysis, and X-ray diffraction analysis, and by measuring the solubility and hygroscopy. The infrared and NMR spectra and X-ray diffraction pattern of the enantiomer were distinctly different from those of the racemate. The melting point of the enantiomer was lower than that of the racemate by 5 degrees C, while the solubility of the enantiomer was 1.3 times higher than that of the racemate. The hygroscopic rate of the enantiomer was greater than that of the racemate. These results suggested that ST was classified into a racemic compound crystal. Furthermore, by comparing the relative peak intensity ratios on X-ray diffraction patterns of the crystals with various optical purities prepared by recrystallization, it was found that a mixture of racemic compound crystals and either of racemic mixture crystals or racemic solid solutions was obtained by recrystallization of ST in the content of 0 to 64%ee, while the recrystallization of ST in the content of more than 64%ee led to the formation of racemic mixture crystals or racemic solid solutions.
通过红外光谱、固态13C CP/MAS NMR光谱、热分析和X射线衍射分析，并测量溶解度和吸湿性，研究了甲苯磺酸舒普拉泰（ST）对映体和外消旋体的物理化学性质。对映体的红外光谱、NMR光谱和X射线衍射图谱与外消旋体明显不同。对映体的熔点比外消旋体低5℃，而对映体的溶解度比外消旋体高1.3倍。对映体的吸湿率大于外消旋体。这些结果表明ST属于外消旋化合物晶体。此外，通过比较重结晶制备的具有不同光学纯度的晶体的X射线衍射图谱上的相对峰强度比，发现ST在0至64%ee含量下重结晶得到外消旋化合物晶体与外消旋混合物晶体或外消旋固溶体之一的混合物，而ST在大于64%ee含量下重结晶导致形成外消旋混合物晶体或外消旋固溶体。
