Patent ID: 7351398

Claim:
A composition comprising: (1) a radiopharmaceutical precursor comprising a chelator not covalently linked to a targeting moiety or domain; and (2) a stabilizing amount of a hydrophilic thioether of the formula R—S—CH 2 C(R 1 R 2 R 3 ) wherein: R is C 1 to C 4 alkyl or a C 1 to C 4 alkyl containing at least one hydrophilic group selected from —COOH, —NH 2 , —NHR 4 , —NR 4 2 , —OH, —SO 2 R 4 , —SOR 4 , —SO 3 H, —CONH 2 , —CONHR 4 , —CONR 4 2 , —COOR 4 , —OR 4 , —SR 4 , —NO 2 , —SO 2 NH 2 , —SO 2 NHR 4 and —SO 2 NR 4 2 ; with the proviso that, when R is methyl, the hydrophilic group is not —NH 2 , —NHR 4 , NR 4 2 or —OH; R 1 , R 2 , and R 3 are each independently selected from the group consisting of —H, —COOH, —NH 2 , —NHR 4 , —NR 4 2 , —OH, —SO 2 R 4 , —SO 3 R 4 , —SO 3 H, —CONH 2 , —CONHR 4 , —CONR 4 2 , —COOR 4 , —OR 4 , —SR 4 , —NO 2 , —SO 2 NH 2 , —SO 2 NHR 4 , —SO 2 NR 4 2 , C 1 to C 4 alkyl, and a C 1 to C 3 alkyl containing at least one hydrophilic group selected from —COOH, —NH 2 , —NHR 4 , —NR 4 2 , —OH, —SO 2 R 4 , —SO 3 R 4 , —SO 3 H, —CONH 2 , —CONHR 4 , —CONR 4 2 , —COOR 4 , —OR 4 , —SR 4 , —NO 2 , —SO 2 NH 2 , —SO 2 NHR 4 and —SO 2 NR 4 2 ; with the proviso that only one of R 1 , R 2 , and R 3 is —NH 2 , —NHR 4 , —NR 4 2 or —OH; and R 4 is selected from the group consisting of C 1 to C 3 alkyl; and with the further proviso that the hydrophilic thioether comprise at least one of said hydrophilic groups.