This Small Business Innovation Research (SBIR) Phase II project aims to develop a generator to produce pure radium-223 for use in cancer therapy. The alpha-emitter Ra-223 has a longer half-life than the other alpha-emitting radioisotopes (213 Bi, 212Bi and 211At) that are currently being evaluated for use in radio-immunotherapy (RIT), and has been shown to have higher bone uptake than the commercially available beta-active bone seekers. This makes it very attractive for Ra-223 to be developed further for radiopharmaceutical applications and for use as a pain palliation agent. However, the research and clinical application of this isotope are hindered by the limited availability of pure Ra-223. A simple technique to produce the isotope is a generator where a suitable parent, in this case Ac-227, is immobilized on an ion exchanger column and Ra-223 is eluted when required. Current separation methods frequently use organic resins, which tend to degrade under ionizing radiation and thus the product may contain impurities. Prior Phase I work developed new hybrid inorganic/organic ion exchange materials with high affinity for actinium, but low affinity for radium and good resistance against radiation. The Phase II project will optimize the exchanger performance and fabricate a prototype of the Ra-223 generator.<br/><br/>The commercial application of this project will be in the area of cancer therapy. It is expected that the easy - to - use generator, which poses a smaller radiation hazard to personnel, will be used at medical research centers, radio - pharmacies and hospitals to produce pure radium - 223 to treat patients with bone metastases and other small solid tumors.