The Use of Radiolabelled Compounds in the Investigation of Metabolism and Drug-Drug Interactions <i>In</i> <i>Vitro</i>

The investigation of the metabolic characteristics of a drug candidate using in vitro methods provides much valuable information and through human in vitro in vivo extrapolation (IVIVE) allows the prediction of the drug’s metabolic behaviour and effect on other drugs in patients once administered clinically. The quality and hence utility of the data that are obtained from several in vitro studies is typically greatly enhanced by the use of a radiolabelled compound. Hence the initial financial outlay required to synthesise a radiolabelled analogue of the drug candidate should be seen as a judicious investment. The advantages that the use of a radiolabelled form of the drug candidate brings are considered in this publication.