Production of 177Lu and formulation of Ethylene diamine tetramethylene phosphonate [EDTMP] kits as a bone-seeking radiopharmaceutical

Owing to its favourable decay characteristics 177Lu [T1/2= 6.71 d, Ebeta[max]= 497 keV] is an attractive radionuclide for various therapeutic applications. Ethylene diamine tatramethylene phosphonate [EDTMP] is one of the most widely used ligands which form stable complexes with various radionuclides and all the complexes. Enriched 176Lu2O3 was dissolved in 0.1 N HCl and evaporated several times and 176LuCl3 target was irradiated at 2.6x1013 n.Cm- 2.S-1 thermal neutron flux for 14 days.177LuCl3 was dissolved in 1N HCl. EDTMP was dissolved in double distilled water at pH=7.5-8.5 and freeze-dried kits was radiolabeled with 177LuCl3. Distribution studies were done in healthy mice. The yield of 177Lu was [220 TBq/g; 6000 Ci/g], the radionuclidic purity was 99%.The radiolabeling yield of EDTMP kits at 37°C after 30 min and 4 hours was 98 +/- 0.5% and after 72 hours was 90 +/- 2.1%, the in vitro stability in human serum at 37°C up to 72 hours post radiolabeling was 85 +/- 1.8%.The biodistribution studies of 177Lu-EDTMP and 177LuCl3 in normal mice showed skeleton uptake and low soft-tissue concentration. In this study, we produce 220 TBq/g [6000 Ci/g] of 177Lu by neutron activation of 176Lu in the Tehran Research Reactor. Our results showed 177Lu-EDTMP as a bone-seeking radiopharmaceutical. Due to its suitable nuclear characteristics 177Lu appears to be worthwhile for palliative therapy of bone metastasis

Three different procedures in labeling of ubiquicidin with technetium 99m: a comparative study

UBI 29-41 [a derivative of antimicrobial peptide ubiquicidin] labelled with 99mTc is reported to discriminate between bacterial infections and sterile inflammatory processes. In this study, three lyophilized kit were performed, one of them based on the direct labelling with only SnCl[2] as reducing agent, and other two based on 6-hydrazinopyridine-3-carboxylic acid [HYNIC] and tricine as a coligands with or without ethylenediamine-N,N'-diacetic acid [EDDA]. Synthesis of UBI 29-41 was performed on solid phase using a standard Fmoc strategy. BOC-HYNIC was conjugated with peptide in solution. Three lyophilized kits were prepared as follows: kit 1:40 micro g UBI 29-41, 5 micro g SnCl[2], pH = 9; kit 2: 40 micro g UBI 29-41, 40 micro g SnCl[2], 20 mg tricine, pH = 5.2; kit 3: 40 micro g UBI 29-41, 40 micro g SnCl[2], 15 mg tricine, 5 mg EDDA, pH = 7. With addition of 99mTcO[4]-solution, kits were labeled under specific conditions, and the radiochemical purity was evaluated by ITLC and HPLC methods. Stability and protein binding in human serum followed by in vitro binding to bacteria were assessed. Biodistribution of radiopeptides in staphylococcus aureus infected rats muscles were studied using ex vivo counting and scintigraphy. Radiochemical analysis indicated rapid and high labeling yield [>95%] for the three kits. Binding to bacteria for kit 2 was to some extent higher than that was obtained for the two other kits. Specific accumulation in infected thigh muscles, as indicated by T/NT ratios was 3.29, 4.6 and 3.77 for kit 1, 2 and 3, respectively. The HYNIC-UBI 29-41 labeled in presence of tricine as coligands [kit 2] showed the most promising results for further in vivo evaluation