This text defines the role and scope of nuclear medicine imaging techniques (gamma scintigraphy) in pharmaceutical research, giving information from clinical trial data. No other technique can localize so precisely the site of disintegration of a tablet in the gastro-intestinal tract, the penetration of an aerosol in the lung or the residence time of a drug on the cornea. The book covers all aspects of scintigraphic imaging applied to pharmaceutical research, ranging from the regulatory requirements, ethical submission, and study approval in normal human subjects and patients groups, through to detailed descriptions of specific applications. It provides descriptions of the basic instrumentation, techniques, the principles of GMP applied to radiolabelling procedures and the importance of validation of products and procedures.