Pressed Solid Target Production of 89Zr and its Application for Antibody Labelling.

Objectives: Zirconium-89 ( 89Zr, t1/2=3.27d) is an important + emitting radionuclide used in Positron Emission Tomography (PET) immuno studies due to its unique characteristics and increased demand due to simple and cost-effective production capacity. Production of 89Zr is achieved primarily through solid natural yttrium targets via different target preparation methodologies, such as electrodeposition, pressed foils, and spark plasma sintering. In this study, we have investigated the pressed solid target methodology.

Methods: The Yttrium Oxide (Y2O3) powder was pressed to pellet form and stacked over a different back support plate, such as platinum (Pt), niobium (Nb), and tantalum (Ta). The target was irradiated with approximately 12 MeV proton beam for 10-60 minutes at 20µA current. The irradiated target was purified through a solid phase extraction method via hydroxamate-based resin by manual or automatic approach. The purified 89Zr was analyzed using gamma scintigraphy, and specific activity was calculated through Deferoxamine (DFO) chelation.

Results: 89Zr radionuclide via pressed target was effectively produced with a production yield of 20-30 MBq/µA.h, and the purification was achieved in 35 minutes with (87.46)% average recovery and >98% purity while using automated purification, but manual purification took 2 hours with (91 ± 2)% recovery and >98% purity. The production yield was comparable to the reported pressed target approach. Deferoxamine (DFO) chelation with 89Zr-oxalate was performed with purity >98% and specific activity of 25-30 µCi/mmol.

Conclusion: In this study, we explored the production of 89Zr by pressed targets and purification via manual or automated methods with good radionuclide purity. The chelation with DFO or its analog was performed with good labeling efficiency and stability

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