Kiguchiya Akihito, Teraoka Reiko, Sakane Toshiyasu, Yonemochi Etsuo
Technology Research & Development Division, Sumitomo Dainippon Pharma Co., Ltd.
Department of Pharmaceutical Technology, College of Pharmaceutical Sciences, Himeji Dokkyo University.
Chem Pharm Bull (Tokyo). 2019;67(9):945-952. doi: 10.1248/cpb.c18-00743.
Salt and cocrystal formulations are widely used as techniques to improve physicochemical properties of compounds. Some spectrometric techniques to distinguish cocrystals from salts have been reported; however, it has not been possible to adapt these formulations with many compounds, because of limitations, high difficulty, and exceptions. Therefore, we focused on the possibility of UV spectrometry, which had not been reported as a classification technique for salts and cocrystals. The integration values of solid-state UV/visible (Vis) spectra of indomethacin salts were larger than those of physical mixtures of indomethacin and counter molecules, while that of indomethacin cocrystal was not large compared with that of the physical mixture. From these results, differences between a salt and a cocrystal were observed in their solid-state UV/Vis absorption spectra for indomethacin complexes. Therefore, it is suggested that solid-state UV/Vis absorption spectra can be used as a new technique to classify salts and cocrystals.
盐和共晶制剂作为改善化合物物理化学性质的技术被广泛使用。已经报道了一些区分共晶和盐的光谱技术；然而，由于存在局限性、高难度和例外情况，无法将这些制剂应用于许多化合物。因此，我们关注了紫外光谱法的可能性，此前尚未有将其作为盐和共晶分类技术的报道。吲哚美辛盐的固态紫外/可见（Vis）光谱积分值大于吲哚美辛与抗衡分子物理混合物的积分值，而吲哚美辛共晶的积分值与物理混合物相比并不大。从这些结果可以看出，吲哚美辛配合物的盐和共晶在固态紫外/可见吸收光谱上存在差异。因此，建议固态紫外/可见吸收光谱可作为一种区分盐和共晶的新技术。
