In Vitro and In Vivo Behaviour of I111n Complexes of TTHA,
TTHA-Bis(Butylamide) and TTHA-Bis(Glucamide): Stability,
Biodistribution and Excretion Studied by Gamma Imaging
M. I. M. Prata,1,2M. J. Ribeiro,1A. C. Santos,1J. A. Peters,3F. Nepveu,4C. F. G. C. Geraldes,2and J. J. P. de Lima1
Received30 Apr 1998
Accepted11 May 1998
Abstract
Aiming at radiopharmaceutical application, I111n3+ complexes of the
polyaminocarboxylates TTHA, TTHA-bis(butylamide) and TTHA-bis(glucamide) were
investigated. The in vitro stability of I111n(TTHA)3− and I111n(TTHA-bis(butylamide)- was
evaluated by measuring the exchange of I111n3+ from the complexes to transferrin and the
results were compared with those for I111n(DTPA)2−. We also performed biodistribution studies of
the three I111n3+ complexes by gamma-imaging in Wistar rats and by measuring the
radioactivity in their organs. TTHA and its derivatives seem to have similar in vivo biodistribution with prevailing renal excretion.