Radiopharmaceutical and methods

An aqueous pharmaceutical composition comprising:

• (a) a complex of lutetium-177 and EuK-Sub-kf-iodo-y-DOTAGA which is enriched in isomer (2A),
• which complex is produced by an incorporation reaction comprising
• (i) combining lutetium-177 and EuK-Sub-kf-iodo-y-DOTAGA, wherein the EuK-Sub-kf-iodo-y-DOTAGA is enriched in isomer (1A),
• in a reaction buffer having a final concentration of one or more ascorbate compounds of 55 mg/mL to 75 mg/mL and in the absence of a gentisate compound;
• (ii) heating the reaction composition to a temperature no greater than 90° C. to form the complex, which complex has 99% or greater lutetium-177 incorporation;
• (b) one or more ascorbate compounds present in a total concentration from 55 mg/mL to 75 mg/mL of the pharmaceutical composition;
• and
• (c) one or more gentisate compounds present in a total concentration of 16 mg/mL to 36 mg/mL of the pharmaceutical composition;
• wherein the complex formed in step (a), after being formed and cooled, is admixed with the ascorbate and gentisate compounds and brought to a volume such that the resulting pharmaceutical composition has a volumetric radioactivity of 250 to 1000 MBq/mL and the radiochemical purity of the pharmaceutical composition is at least 95% following storage at a temperature of 30° C. for 3 days following preparation of the composition.