Radiopharmaceutical enhancement by drug delivery systems: A review

Introduction: Drug delivery systems are entities designed to alter the biological behaviour of the pharmaceutical active ingredients that they carry in order to afford more beneficial biodistribution and safety profiles. Many problems currently faced by the field of nuclear medicine (e.g. developing new theranostic agents, utilizing multimodal imaging platforms and providing targeted delivery) can be facilitated by applying drug delivery systems to radiopharmaceuticals that have been proven successful in other medical fields. This review describes the advancements being made towards this goal. Areas covered: All aspects of drug delivery systems (liposomes, nanoparticles, microspheres) in the field of nuclear medicine are discussed. Only systems with foreseen or confirmed clinical applications in nuclear medicine are discussed, not instances where nuclear imaging is merely a tool to evaluate the biodistribution of novel delivery technologies. Conclusion: Great advancements have been made with the development of novel systems incorporating nuclear entities in drug delivery systems, with the possibility of reshaping the nuclear medicine landscape. Nonetheless, translation from preclinical evaluations to clinical use is lacking and serious investment needs to be made towards this goal.