Hu Yuerong, Wikström Håkan, Byrn Stephen R, Taylor Lynne S
Department of Industrial and Physical Pharmacy, Purdue University, West Lafayette, IN 47907-2091, USA.
J Pharm Biomed Anal. 2007 Nov 30;45(4):546-51. doi: 10.1016/j.jpba.2007.07.028. Epub 2007 Aug 3.
Polymorphism is a frequently encountered phenomenon in organic materials and is particularly important for pharmaceuticals. For enantiotropically related polymorphs, one important property of the polymorphic pair is the thermodynamic transition temperature. The transition temperature is sometimes difficult to determine experimentally due to the rapid transformation between the two polymorphic forms in solution. Due to its relatively rapid spectral acquisition rate, as well as the possibility of in-line monitoring, Raman spectroscopy is ideally suited to monitoring the kinetics of transformation between different solid-state forms. In this study, it was demonstrated that the transition temperature could be estimated from polymorphic transformation profiles obtained from real-time in situ Raman data. Using this method, the estimated transition temperature for flufenamic acid was in good agreement with the previously published value. These results suggest that Raman spectroscopy may be a useful method to determine transition temperatures in systems not amenable to other methods.
多晶型现象是有机材料中经常遇到的现象，对药物而言尤为重要。对于对映异构相关的多晶型物，多晶型物对的一个重要性质是热力学转变温度。由于两种多晶型形式在溶液中快速转变，转变温度有时很难通过实验确定。由于拉曼光谱具有相对较快的光谱采集速率以及在线监测的可能性，它非常适合监测不同固态形式之间的转变动力学。在本研究中，结果表明可以从实时原位拉曼数据获得的多晶型转变曲线来估算转变温度。使用这种方法，氟芬那酸的估算转变温度与先前公布的值吻合良好。这些结果表明，拉曼光谱可能是一种用于确定其他方法不适用的体系中转变温度的有用方法。
