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

Abstract 

Introduction

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

Methods

^99mTc from an equilibrium mixture of ⁹⁹Mo/^99mTc 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. ^99mTc thus obtained was used for labeling standard ligands such as dimercaptosuccinic acid (DMSA) and ethylene dicysteine (EC), to ascertain the usability.

Results

Selective deposition of ^99mTc 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 ^99mTc 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 ^99mTc-labeled formulations such as ^99mTc-DMSA and ^99mTc-EC was found to be satisfactory in terms of high labeling yields (>98%).

Conclusion

A novel and attractive method has been developed to obtain highly concentrated ^99mTc, without using fission-produced ⁹⁹Mo.

Keywords: Electrode potential, Electrochemical, ⁹⁹Mo/^99mTc generator, Postelution concentration, Radionuclidic purity