Carbon-14 studies (ADME/hAME) provide data for mass balance, pharmacokinetics and metabolite identification. This allows the detailed understanding of the metabolism of a drug candidate which regulators expect.
A synthesis of the drug candidate is designed which uses a radioactive starting material to introduce one or more carbon-14 atoms into the final structure. The labelling position is chosen to maximise the metabolic data that can be determined. The material produced has the same pharmacokinetic and metabolic properties as the unlabelled compound, but the presence of the radioactive element allows quantification of the parameters being studied.