Validation and application of a solid phase chemistry method for preparation of high effective specific activity technetium-99m radiopharmaceuticals

Solid phase chemistry with UltraLink(TM) Iodoacetyl gel was investigated as a method for removing excess ligand present in preparations of diaminedithiol (DADT) Tc-99m radiopharmaceuticals. The process was optimized and tested under Tc-99m labeling conditions with 2,2,4,9,9-pentamethyl-4,7-diaza-1,10-decanedithiol (N-methyl-DADT), 1, and 4-(1-(2'-methoxyphenyl) piperazinylbutyl)-2,2,9,9-tetramethyl-4,7-diaza-1,10-decanedithiol (DADT-4C-MPP), 2, a serotonin receptor binding ligand. The results illustrated that this gel removed greater than or equal to 99.9% excess ligand used in labeling reactions, and was comparable to the level of purification usually obtained by the more labor intensive method of HPLC. (C) 1997 Elsevier Science Inc.