A Mass-Production Process of a Highly Pure Medical Use ^99mTc from Natural Isotopic Mo(n, γ) ⁹⁹Mo without Using Uranium

抄録

A new method to produce highly pure ^99mTc of maximum 500Ci(1.85e＋13Bq) per batch from a low specific activity ⁹⁹Mo made from natural-Mo(n, γ) method is presented in this study.Authors developed a novel procedure to provide ^99mTc of high specific activity and purity from ⁹⁹Mo with a low specific activity obtained by the(n, γ) method. This process named TcMM(technetium master milker) with a new principle found out by the authors involves the selective adsorption of ^99mTc onto an activated charcoal column, followed by an elution of ^99mTc by warm alkaline solution, and final purification through an alumina column, which would be applicable to routine production of a large amounts of ^99mTc from ^natMo(with ⁹⁹Mo) within a short processing time and with a low cost.By the experiment using a high radioactivity of ⁹⁹Mo of 1e＋12Bq levels, a highly pure ^99mTc free from ^natMo(with ⁹⁹Mo) was obtained in a sterile saline solution within 30 - 50min. as the chemical form of ^99mTcO₄⁻, and the average ^99mTc milking rate repeated 10 times got 93.5% and the radiochemical purity of the range of 6N - 7N.In the labeling experiments using several radiopharmaceutical kits,^99mTc collected from the TcMM process gave the target medicines in a highly radiochemical purity.As the result of investigating the disposition behaviors of the above-mentioned ^99mTc-pharmaceuticals using small animals(mouse), ^99mTc collected from TcMM gave the same result as it eluted from the conventional ^99mTc generator.The findings in this study suggest that the present method using natural isotopic ⁹⁸Mo(n, γ)⁹⁹Mo reaction would constitute as an alternative to the Fission Method using HEU to provide ^99mTc useful for clinical studies.