223Ra has been applied for the treatment of metastatic prostate cancer which has spread to bone. The 223Ra is separated from the 227Ac/227Th parents. One separation method uses TRU resin to remove any 231Pa impurity from 227Ac/227Th followed by immobilization of the Ac/Th on Actinide resin and elution of 223Ra with 1M HCl.
Another separation method stores 227Ac in solution and separates 227Th using UTEVA resin and 227Ac using DGA resin, while 223Ra passes through both resins. The 227Th and 227Ac are recovered for ingrowth and further 223Ra production. In both generator options, further purification using strong acid cation exchange or other method to ensure 223Ra with very low 227Ac and 227Th impurity.
 Henriksen, G.H., Hoff, P., Alstaad, J., Larsen, R.H., 2001. 223Ra for endoradiotherapuetic applications prepared from an immobilized 227Ac/227Th Source. Radiochim. Acta, 89, 661-666.
 Eichrom Application Note AN-1617, “227Th/223Ra Generator,” http://www.eichrom.com/wp-content/uploads/2018/02/an-1617_th-227-ra-223-generator.pdf