Accelerators for forming cationic technetium complexes useful as radiodiagnostic agents

Claim 1

A composition for preparing cationic lipophilic technetium complexes for radiodiagnostic imaging, said composition comprising an admixture of (a) an accelerator compound selected from the group of water-soluble organic bidentate ligands that are capable of coordinating with technetium to form a 4 to 6 member ring and (b) a target-seeking ligand or aqueous salt thereof, having the following structure: ##STR9## wherein: i is an integer from 1 to 6; R, R 1 , R 2 , R 3 , R 4 , R 5 and R 6 are each independently selected from hydrogen or substituted or unsubstituted alkyl, aryl, alkylaryl, arylalkyl, monocycloalkyl, polycycloalkyl, heterocyclic and carbocyclic groups, and R plus R i may be taken together to form a cyclic compound or separately to form a linear compound; Y 1 , Y 2 , Y 3 , Y 4 , Y 5 and Y 6 are independently selected from substituted or unsubstituted alkyl, aryl, alkylaryl, arylalkyl, monocycloalkyl, polycycloalkyl, heterocyclic and carbocyclic groups; A 1 , A 2 , A 3 , A 4 , A 5 and A 6 are each, independently, a neutral donor atoms having a free-electron pair available for complexing with TC-99m or TC-99 to form a cationic complex; and k 1 , k 2 , k 3 , k 4 , k 5 and k 6 are each independently zero or one; or ##STR10## wherein: R, R', R" and R'" are independently selected from hydrogen or substituted or unsubstituted alkyl, aryl, alkylaryl, arylalkyl, monocycloalkyl, polycycloalkyl, heterocyclic and carbocyclic groups; A, A', A" and A'" are independently selected from the group of neutral donor atoms having a pair of electrons available for complexing with Tc-99m or TC-99 to form a cationic complex; B is an atom selected from the group of neutral donor atoms having a pair of electrons available for complexing with Tc-99m or TC-99 or from the elements listed in Group IV A of the periodic table; n, n', n" and n'" are independently the integer 1 or 2; and m is 0 or 1; said accelerator compound having a weaker coordinating bond with technetium than the target-seeking ligand.

Claim 16

A method for making a cationic complex labelled with Tc-99m for radioscintigraphic imaging, said method comprising admixing 99m Tc-pertechnetate and the composition of any one of claims 1 through 14 and placing the resulting admixture in a constant temperature water bath for a period of time sufficient to form such labelled complex.