Polymorphism is the ability of a molecule to exist in more than one stable or meta-stable crystalline state. Distinct crystalline forms commonly exhibit different properties that are pharmacologically significant. These properties include bioavailability, solubility, rate of absorption, duration, and stability. In many cases the Raman spectra can distinguish between many different existing forms as well as the possibility of identifying new potentially unknown polymorphs. The attached Application Note is an example of using the Nicolet iS50 Raman Module to identify different polymorphs in a model compound.