Characterization of the solid-state: spectroscopic techniques.

The physical characterization of pharmaceutical solids is an integral aspect of the drug development process. This review summarizes the use of solid-state spectroscopy techniques used in the physical characterization of the active pharmaceutical ingredient, excipients, physical mixtures, and the final dosage form. A brief introduction to infrared, Raman, and solid-state NMR experimental techniques are described as well as a more thorough description of qualitative and quantitative applications. The use of solid-state imaging techniques such as IR, Raman, and TOF-SIMS is also introduced to the reader.