A novel electrochemical technique for the production of clinical grade 99mTc using (n, gamma)99Mo

In order to meet the growing demand for (99m)Tc and to reduce the reliance on fission-produced (99)Mo, an electrochemical pathway for accessing (99m)Tc through the (n, gamma)(99)Mo was explored as a back-up measure and to supplement (99m)Tc supply for radiopharmaceuticals application.

(99m)Tc from an equilibrium mixture of (99)Mo/(99m)Tc was selectively deposited on a platinum cathode in an electrochemical cell by applying optimal voltage and stripped back again into the 0.9% saline solution. The radiochemical and radionuclidic purity of the product were determined using standard techniques. (99m)Tc thus obtained was used for labeling standard ligands such as dimercaptosuccinic acid (DMSA) and ethylene dicysteine (EC), to ascertain the usability.

Selective deposition of (99m)Tc on the platinum electrode was achieved at a potential of 5 V over a period of 1 h in NaOH electrobath. The overall yield of (99m)Tc was >90%, with >99.99% radionuclidic purity and >99% radiochemical purity. The performance of the generator remained consistent over a period of 10 days. The compatibility of the product in the preparation of (99m)Tc-labeled formulations such as (99m)Tc-DMSA and (99m)Tc-EC was found to be satisfactory in terms of high labeling yields (>98%).

A novel and attractive method has been developed to obtain highly concentrated (99m)Tc, without using fission-produced (99)Mo.