Abstract: A stabilized radiopharmaceutical composition, a kit including same, and a method for making same, where the radiopharmaceutical is (i) susceptible to either reductive degradation or radiolysis and which includes a metal complex of a radionuclide with a ligand, (ii) a first stabilizer for the radiopharmaceutical which is an amino-substituted aromatic carboxylic acid or a salt, ester or amide thereof, and (iii) a second stabilizer for the radiopharmaceutical which is a diphosphonic acid or salt thereof. The first and second stabilizers are present in an amount effective to stabilize the radiopharmaceutical, and the radiopharmaceutical is not a metal complex of the diphosphonic acid.

Abstract: A peptide-chelate conjugate with affinity for the ST receptor is disclosed, wherein the chelate is tetradentate. The peptide-chelate conjugate of the invention may be labelled with a radiometal to provide a metal complex. A radiopharmaceutical composition comprising the metal complex is provided. which is suitable for the diagnostic imaging of colorectal cancer. Also provided for in the invention is a kit for the preparation of the radiopharmaceutical preparation.