Zhou Mengqing, Ao Ju, Liu Song, Wu Chaogang, Lai Anping, Gao Haitao, Zhang Guoqing
a Engineering Research Center for Eco-Dyeing and Finishing of Textiles, Ministry of Education, Zhejiang Sci-Tech University , Hangzhou , China and.
b Zhejiang Apeloa Medical Technology Co, Ltd , Jinhua , China.
Pharm Dev Technol. 2017 Feb;22(1):58-62. doi: 10.3109/10837450.2016.1146295. Epub 2016 Feb 24.
Only one crystal form of metoprolol succinate (Form I) was reported during previous researches and production. In this study, a new polymorph of metoprolol succinate (here named as Form II) was discovered and investigated by X-ray diffraction, thermoanalysis and infrared spectroscopy. The results show its crystal structure and thermal properties are significantly different with Form I. Compared with Form I, Form II exhibits specific diffraction pattern, lower melting temperature and weaker hydrogen bond effect. The thermostability testing suggests Form II is a metastable crystal form and will gradually transform into Form I undergoing treatment of high temperature and humidity. Metastable crystal form generally has better dissolubility than its corresponding stable form. Subsequent measurement also verified that Form II can dissolve in the water more quickly than Form I.
在以往的研究和生产过程中，仅报道过琥珀酸美托洛尔的一种晶型（晶型I）。在本研究中，发现了琥珀酸美托洛尔的一种新多晶型物（此处命名为晶型II），并通过X射线衍射、热分析和红外光谱对其进行了研究。结果表明，其晶体结构和热性质与晶型I有显著差异。与晶型I相比，晶型II呈现出特定的衍射图谱、较低的熔点温度和较弱的氢键效应。热稳定性测试表明，晶型II是一种亚稳晶型，在高温和高湿处理下会逐渐转变为晶型I。亚稳晶型通常比其相应的稳定晶型具有更好的溶解性。后续测量也证实，晶型II在水中的溶解速度比晶型I更快。
