Complexation of lutetium-177 with bifunctional chelators in the presence of Mg, Cu, and Yb

Watanabe, Satoshi; Hashimoto, Kazuyuki; Ishioka, Noriko

As part of basic studies for the production of Lu capable of labeling of Lu-1,4,7,10-tetraazacyclododecan-N,N',N'',N'''-tetraacetic acid (DOTA)-antibody, Lu complexation of DOTA and diethylenetriamine-N,N,N',N'',N''-pentaacetic acid (DTPA) was investigated in the presence of competing metals: Mg, Cu, and Yb in addition to Ca, Fe, and Zn. The inhibition of Lu complexation by the competing metals was in the order of Mg, Ca Fe Yb Cu, Zn and Mg, Ca Zn Fe Cu Yb with DOTA and DTPA, respectively. Consequently, the elimination of Mg and Ca from the Lu final solution produced was not found to be necessary, while the elimination of Cu, Fe, Zn and Yb from the Lu final solution was found to be necessary. On the basis of the knowledge obtained, the method of elimination of the competing metals will be developed.