Purification procedure for the preparation of the radioactive tracer 3' -deoxy-3' - 18F luorothymidine (18F FLT)

摘要

A procedure for the preparation of the radioactive tracer 3-deoxy-3-[18F]fluorothymidine ([18F]FLT) comprises the following steps: a) preparation of anhydrous [18F]F-fluoride; b) labelling of a precursor, for example 3-N-Boc-1-[5-O-(4,4-dimethoxytrityl)-3-O-nitrophenylsulfonyl-2-deoxy--D-lyxofuranosyl]thymidine; c) hydrolysis of the mixture obtained by means of the previous steps; d) purification of the mixture to obtain the radioactive tracer [18F]FLT. In this procedure steps a), b) and c) are carried out by means of known methods. In step d) the mixture obtained after step c) is purified by means of the passage through a ventilated filter and one or more cartridges of the cationic exchange type (e.g. a Chromafix PS-H+), one or more cartridges of the reversed phase type, and finally a passage through cartridges either of the alumina N type, or diol cartridges, or anionic exchange cartridges or a combination thereof. Furthermore, the mixture which is present in the cartridges is eluted with H2O for injection, whereby the resulting product is forwarded to a container or ampoule for the collection of [18F]FLT.