Tetraethylester of DOTP was prepared and properties of its complexes with radioisotopes of Sm and Ho were investigated : stability in solution, complexation and decomplexation rates, in vitro and in vivo (mouse) properties.
A very low binding of these complexes to hydroxyapatite (HA) and calcified tissues was observed confirming the assumption that a fully ionized phosphonate group(s) is necessary for a strong bone affinity. Both complexes show similar behaviour in vivo and, in general, follow the biodistribution trend of the H4dota complexes with the same metals.