Drug substance solid-state characteristics hydrate

Infrared (IR) absorption spectroscopy, especially measured by FTIR, is a powerful technique for the physical characterization of pharmaceutical solids.When the structural characteristics of a solid perturb the pattern of vibrational motion for a given molecule, these alterations can be used as a means to study the solid-state chemistry of the system. FTIR spectra often are used to evaluate the type of polymorphism that exists in a drug substance and can be very useful to study the water contained within hydrate species. Solid-state IR absorption spectra often are obtained on powdered solids through the combined use of FTIR and diffuse reflectance detection, and interpreted through conventional group frequency compilations. ... 

In the following sections, the solid-state physicochemical characteristics of drug substances and their physical changes related to polymorphism, hydrates, amorphous form, and the effect of water will be discussed. 

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