Abstract: The complex ^99m TcN-CPDTC(CPDTC: N-cyclopropyl dithiocarbamate trihydrate) is synthesized through ligand exchange reaction. The two-step procedure involves the initial reaction of ^99m TcO₄^- with succinic dihydrazide(SDH) as a donor of nitrido ligand(N^3-) in the presence of stannous chloride dihydrate as reducing agent and propylenediamine tetraacetic acid(PDTA) as complex agent, followed by the addition of sodium N-cyclopropyl dithiocarbamate trihydrate. The radiochemical purity(RCP) of the product is over 90% as measured by thin layer chromatography(TLC). It is stable over 6 h at room temperature. Its partition coefficient indicates it is a good lipophilic complex. The biodistribution results in mice indicate that ^99m TcN-CPDTCis significantly retained into the brain. The brain uptake(%, ID/g) is 4.64, 3.54 and 2.59 and the brain/blood ratio is 1.08, 1.27 and 1.28 at 5, 30 and 60 min post injection respectively. These results suggest potential usefulness of the complex as a brain perfusion imaging agent.

Key words: Technetium-99m, Technetium nitrido complex, Radiopharmaceutical, Biodistribution