Stephenson G A, Stowell J G, Toma P H, Pfeiffer R R, Byrn S R
Lilly Research Laboratories, Lilly Corporate Center, Indianapolis, IN 46285, USA.
J Pharm Sci. 1997 Nov;86(11):1239-44. doi: 10.1021/js9701667.
The crystal structures of the commercially available form of erythromycin A dihydrate and clarithromycin anhydrate, in addition to the structure of erythromycin B dihydrate, are reported in this paper. In light of the crystallographic data, analysis of the structural information provides insight into the physical properties of these pharmaceuticals. The propensity of these pharmaceuticals to form solvated structures is discussed and the hygroscopicity of erythromycin A dihydrate is investigated. Solid-state 13C NMR was used to monitor changes that occur when the dihydrate form of erythromycin A is stored under conditions of low relative humidity. Although erythromycin A dihydrate retains its crystallographic order at low humidity, as indicated by its X-ray powder diffraction pattern, the local chemical environment is dramatically influenced by the loss of the water molecules and results in dramatic changes in its solid-state 13C NMR spectrum.
本文报道了市售的红霉素A二水合物和克拉霉素无水物的晶体结构，以及红霉素B二水合物的结构。根据晶体学数据，对结构信息的分析有助于深入了解这些药物的物理性质。讨论了这些药物形成溶剂化结构的倾向，并研究了红霉素A二水合物的吸湿性。采用固态13C核磁共振技术监测红霉素A二水合物在低相对湿度条件下储存时发生的变化。尽管红霉素A二水合物在低湿度下保持其晶体学有序性，如其X射线粉末衍射图谱所示，但其局部化学环境受到水分子损失的显著影响，导致其固态13C核磁共振谱发生显著变化。
