Development of acetylated HDD kit for preparation of 188Re-HDD/lipiodol.

A lipiodol solution of (188)Re-4-hexadecyl-2,2,9,9-tetramethyl-4,7-diaza-1,10-decanedithiol ((188)Re-HDD/lipiodol) is in clinical study for liver cancer therapy. However, formulation of it is difficult due to highly active and unstable sulfhydryl groups. We produced new kits using diacetylated HDD (AHDD), in which sulfhydryl groups are protected. We found that AHDD kit can replace HDD kit due to an increased stability for formulation, the better radiolabeling efficiency (78%) and the equivalent biodistribution pattern in mice.