Studies on 66,67Ga- and 199Tl-poly(N-vinylpyrrolidone) complexes

Gallium and thallium radionuclides have both diagnostic and therapeutic applications in the field of nuclear medicine. Poly(N-vinylpyrrolidone) (PVP) is routinely used as a drug base because of its excellent biocompatibility. In this paper, complex formation abilities between no-carrier-added 66,67Ga/199Tl radionuclides and PVP have been studied. It has been found that aqueous 5% PVP solution can almost quantitatively back extract 66,67Ga/199Tl radionuclides from an organic phase, which proves the complexing ability of PVP with 66,67Ga/199Tl. Tl3+ is more efficient to form Tl-PVP complexes than Tl+. However, Tl3+-PVP complexes are less stable than Ga3+-PVP complexes.