Laboratory Synthesis of Actinium-225 Complexes with Somatostatin Peptide Analogs for Radionuclidic Therapy of Neuroendocrine Tumors

Somatostatin receptors overexpressed by malignant neuroendocrine neoplasms are a well-known target for radioligand peptide-receptor radionuclide therapy with metal complexes of peptide molecules, e.g., somatostatin analogs and trivalent cations of metal radionuclides. The aim of the present work was experimental production of a potential pharmaceutical composition based on metal complexes of somatostatin analogs DOTA-TATE and DOTA-TOC with the radionuclide 225Ac. Optimal conditions for the radiochemical synthesis of 225Ac complexes with peptides DOTA-TATE and DOTA-TOC with radiochemical yield 95% were established as peptide concentration 1 mg/ml with addition of ascorbate buffer and heating of the reaction mixture at 95°C for 30 min. The results will be in demand in the future for development and technology transfer of the production of radiopharmaceutical drugs to the formulating pharmacy for their clinical use.