区分药物多晶型

Spectroscopic techniques have a great potential for analyzing polymorphic forms and are used more and more frequently for this kind of analysis. Especially IR and Raman spectroscopy offer fast and efficient identification and quantification capabilities. Mid IR spectroscopy, where fundamental molecular vibrations are excited, is a routine method in the Pharmacopoeias for the testing of the chemical identity. But far IR spectroscopy, where back bone vibrations of larger molecules or intermolecular vibrations in crystal lattices are excited, is widely applied to the identification of polymorphic forms and solvates. The new Bruker FM functionality offers the measurement of the complete FIR-MIR spectral range in one step and allows for simultaneous identification and polymorph screening of samples [1]. Nowadays, modern diamond ATR (attenuated total reflection) accessories are used to analyze the substance directly without any sample preparation. In the far IR region vacuum spectrometers are of high advantage. A vacuum far IR spectrometer eliminates disturbing influences of atmospheric water vapor and increases the stability of the measurement significantly while the sensitivity is increased by a factor of two compared to non-vacuum far IR [2].