Due to the complex nomenclature used in various regulations and guidance documents, the understanding of radiopharmaceutical precursor’s definition might be challenging. Depending on the context it could be interpreted as the substance which becomes a radiopharmaceutical after radiolabeling with a radionuclide of choice or a radionuclide which is used for radiolabeling of that substance. In this Chapter we present and discuss the requirements for precursors which are used in the preparation of theranostic radiopharmaceuticals, in particular for preparation of new radiopharmaceuticals for clinical trials within the EU. In discussion on the available methods for assessing the quality of radiopharmaceutical precursors and on the specified limits the reference to Ph. Eur. is made. Since the EANM guidelines for in-house preparation of radiopharmaceuticals also specify the need for testing the quality of radiopharmaceutical precursors, information provided herein might help the radiopharmacist working on the development of new theranostic agents to adequately define identity, strength, quality, purity and stability of the final radiopharmaceutical preparation.
Part of the book: Theranostics