Synthesis, characterization and biodistribution of the cationic technetium(II), 1,10-phenanthroline chelate

Abstract

[⁹⁹Tc(phen)₃]Cl₂ was synthesized by reduction of pertechnetate with sodium borohydride in the presence of an excess of 1,10-phenanthroline and characterized by FAB mass spectrometry, magnetic susceptibility measurements, and i.r./vis/u.v. spectrophotometry. For biodistribution evaluation in mice [^99mTc(phen)₃]Cl₂ could be obtained in a radiochemical purity of 92.5% using a similar procedure. The rather hydrophilic chelate was predominantly excreted by the kidneys. Its low blood retention resulted in a heart/blood activity ratio of 4.2 at 100 min post-injection.