Reproducibility of neutron activated Sm-153 oral dose formulations intended for human administration

► 204 enteric-coated guaifenesin core tablets were irradiated by thermal neutrons. ► Activity measured at 48 h after irradiation was 1.01±0.03 MBq. ► Activity administered per subject was 0.88±0.03 MBq. ► Good reproducibility (CV=3.5%) of Sm-153 radioactivity was obtained. ► Effective doses to volunteers were within dose reference level of 0.8 mSv.