Preparation of clinical-scale 99Mo/99mTc column generator using neutron activated low specific activity 99Mo and nanocrystalline γ-Al2O3 as column matrix

Abstract

Preparation of clinical-scale (99)Mo/(99m)Tc generator using (n,γ) activated low specific activity (99)Mo and nanocrystalline γ-Al(2)O(3) as a high capacity sorbent matrix is attempted. Nanocrystalline γ-Al(2)O(3) was synthesized by 'solid state mechanochemical' reaction of aluminum nitrate with ammonium bicarbonate. Experimental parameters were optimized to effectively separate (99m)Tc from (99)Mo using this sorbent as the column matrix. The performance features of a 13 GBq (350 mCi) (99)Mo/(99m)Tc generator using this sorbent and (99)Mo produced by (n,γ) route having specific activity 12.9-18.5 GBq/g were evaluated for 10 days. The sorbent possessed the requisite selectivity for (99)Mo and demonstrated a maximum sorption capacity of 200 ± 5mg Mo/g, which is ~10 times higher than that of ordinary acidic alumina. The overall yield of (99m)Tc was >80%, with radionuclidic purity >99.99% and radiochemical purity >99%. The yield of (99m)Tc varied from 7.8 to 2.1 GBq in the eluate for the six days of operation of the generator. The radioactive concentration of (99m)Tc eluted was adequate for the formulation of radiopharmaceuticals. The performance of the generator remained consistent over an extended period of 10 days. The eluted (99m)Tc was suitable for the formulation of (99m)Tc-DMSA and (99m)Tc-EC resulting in high radiolabeling yields (>98%). The effectiveness of γ-Al(2)O(3) as a new generation sorbent in the development of clinically useful (99)Mo/(99m)Tc generator using low specific activity (99)Mo and yielding (99m)Tc with adequate radioactive concentration and high purity suitable for formulation of radiopharmaceuticals is demonstrated.