Physical chemical characterization of drug substances

During the development of new drug substances, researchers have typically focused on the biological properties, with less concern for the physical chemical properties. However, in order to understand the behavior of drugs in physiological systems, a broad range of physical chemical properties must be determined. Not all of these properties need to be determined before any clinical studies are initiated; some can be obtained throughout the development process. Others, however, are critical to the early evaluation of the compounds and should therefore be determined as early as possible. This review discusses the nature and timing of the various studies.