Improved titanium-44 purification process for establishing a high apparent molar activity titanium-44/scandium-44 generator.

Sc-radiopharmaceuticals are gaining more interest but still lack availability. The proof of principle of aTi/Sc generator, which can produce Sc daily, has been established but with some limitations and drawbacks. Despite recent advances, separation of Ti from massive quantities of scandium target material is still cumbersome. In this work, the improved radiochemical separation of Ti from residual scandium target material was carried out by precipitation of Sc with fluoride ions. Furthermore, two approaches were used to set up a high apparent molar activity small-scale generator. The first method relied on extraction chromatography for fine purification using a DGA resin, followed by loading of the purified Ti onto a ZR resin column. In the second method, Ti was loaded on the ZR resin directly after the precipitation step. This second method was used to set up a generator of 370 kBq and evaluate by radiolabeling. An apparent molar activity of 2 MBq/nmol was obtained for the radiolabeling with DOTA, the most common and suitable chelate for scandium. This result is comparable with previously published data on  Sc.