The invention is directed to formulations of lipophilic Amyloid beta ligand stilbene and more particularly to formulations which are capable to be administered parenterally e.g. intravenously, wherein the lipophilic Amyloid beta ligand stilbene is a fluorinated stilbene. Further, the invention is directed to a method for sterile filtration of formulations suitable for PET imaging of mammals pursuant to the invention.