Soderquist Chuck Z, McNamara Bruce K, Fisher Darrell R
Isotope Sciences Program, Pacific Northwest National Laboratory, Richland, Washington 99354, USA.
Curr Radiopharm. 2012 Jul;5(3):244-52. doi: 10.2174/1874471011205030244.
Radium-223 is a short-lived alpha-particle-emitting radionuclide with potential applications in cancer treatment. Research to develop new radiopharmaceuticals employing (223)Ra has been hindered by poor availability due to the small quantities of parent actinium-227 available world-wide. The purpose of this study was to develop innovative and cost-effective methods to obtain high-purity (223)Ra from (227)Ac. We obtained (227)Ac from two surplus actinium-beryllium neutron generators. We retrieved the actinium/beryllium buttons from the sources and dissolved them in a sulfuric-nitric acid solution. A crude actinium solid was recovered from the solution by coprecipitation with thorium fluoride, leaving beryllium in solution. The crude actinium was purified to provide about 40 milligrams of actinium nitrate using anion exchange in methanol-water-nitric acid solution. The purified actinium was then used to generate high-purity (223)Ra. We extracted (223)Ra using anion exchange in a methanol-water-nitric acid solution. After the radium was separated, actinium and thorium were then eluted from the column and dried for interim storage. This single-pass separation produces high purity, carrier-free (223)Ra product, and does not disturb the (227)Ac/(227)Th equilibrium. A high purity, carrier-free (227)Th was also obtained from the actinium using a similar anion exchange in nitric acid. These methods enable efficient production of (223)Ra for research and new alpha-emitter radiopharmaceutical development.
镭-223是一种发射α粒子的短寿命放射性核素，在癌症治疗方面具有潜在应用价值。由于全球范围内可用的母体锕-227数量稀少，导致难以获得，这阻碍了研发采用（223）Ra的新型放射性药物的研究。本研究的目的是开发创新且具成本效益的方法，从（227）Ac中获取高纯度的（223）Ra。我们从两个多余的锕-铍中子发生器中获得了（227）Ac。我们从源中取出锕/铍按钮，并将其溶解在硫酸-硝酸溶液中。通过与氟化钍共沉淀从溶液中回收粗锕固体，使铍留在溶液中。使用甲醇-水-硝酸溶液中的阴离子交换法将粗锕纯化，以提供约40毫克的硝酸锕。然后使用纯化后的锕来生成高纯度的（223）Ra。我们在甲醇-水-硝酸溶液中使用阴离子交换法提取（223）Ra。镭分离后，锕和钍随后从柱中洗脱并干燥以便临时储存。这种单程分离产生高纯度、无载体的（223）Ra产物，并且不会干扰（227）Ac/（227）Th平衡。使用硝酸中类似的阴离子交换法，还从锕中获得了高纯度、无载体的（227）Th。这些方法能够高效生产用于研究和新型α发射体放射性药物开发的（223）Ra。
