Preparation and quality control of 153Sm-[tris(1,10 -phenanthroline) samarium (III)] complex

The 153Sm-[tris(1,10-phenanthroline) Samarium(III)]complex (153Sm-PL3) was prepared in view of development of targeting therapeutic compounds for malignancies, and interesting in-vitro anti-tumor activities of lanthanide phenanthroline complexes,. Sm-153 chloride was obtained by thermal neutron flux (4 × 1013 n.cm-2.s-1) of enriched 152Sm2O3 sample, dissolved in acidic media. The labeling was performed in ethanol in 24h, controlled by ITLC (1.0mM DTPA, pH.5, as mobile phase). The partition coefficient for the labeled compound was also determined. A radiochemical yield of more than 95% was obtained. Radiochemical purity of 96% was obtained using ITLC with specific activity of about 27.75 GBq/mg. The radio-labeled complex was stable in aqueous solution at least 24 hours and no significant amount of free 153Sm was released from the complex. The partition coefficient for the labeled compound was determined (log P. 3.4). The complex was stable in final formulation for 66h. The biological evaluation of the compound is under investigation. The radiolabeled compound used in this study was a very inexpensive and useful agent for the use as a therapeutic compound.