Production and quality control (177)Lu (NCA)—DOTMP as a potential agent for bone pain palliation

Skeletal uptake of radiolabeled‐1, 4, 7, 10‐tetraazacyclododecane‐1, 4, 7, 10‐tetramethylene phosphoric acid (e.g., (177)Lu‐DOTMP) complex, is used for bone pain palliation. The moderate energy of β‐emitting [Formula: see text] has been considered as a potential radionuclide for development of the bone‐seeking radiopharmaceutical. Since the specific activity of the radiolabeled carrier molecules should be high, the “no‐carrier‐added radionuclides” have significant roles in nuclear medicine. Many researchers illustrated no‐carrier‐added (177)Lu production; among these separation techniques such as ion exchange chromatography, reversed phase ion‐pair, and electrochemical method, extraction chromatography has been considered more capable than other methods. In order to optimize the conditions, some effective factors on separation of Lu/Yb were investigated by EXC. The NCA (177)Lu, produced by this method, was mixed with [Formula: see text] of DOTMP solution (20 mg in 1 mL of 0.5 M NaHCO(3), [Formula: see text]) and incubated under stirring at room temperature for 45 min. Radiochemical purity of the (177)Lu‐DOTMP complex was determined using radio‐thin‐layer chromatography (RTLC) method. The complex was injected to wild‐type rats and biodistribution was then studied for seven days. The NCA (177)Lu was produced with specific activity of 48 Ci/mg and with a radinuclidic purity of 99.99% through irradiation of enriched (176)Yb target (1 mg) in a thermal neutron flux of [Formula: see text] for 14 days. (177)Lu‐DOTMP was obtained with high radiochemical purities ([Formula: see text]) under optimized reaction conditions. The radiolabeled complex exhibited excellent stability at room temperature. Biodistribution of the radiolabeled complex studies in rats showed favorable selective skeletal uptake with rapid clearance from blood along with insignificant accumulation within the other nontargeted organs. PACS number(s): 87.57.un, 87.57.uq