Solid-phase techniques have been used extensively for radioincorporation of C-11 and F-18 the reaction of radiolabeled intermediates in multi-step raiosyntheses and the purification of radiochemical intermediates by extraction. The incorporation of [I8F]fluoride using modified SAX polystyrene-divinylbenezene resin has dramatically simplified the routine production of [18F]FDG (1). Modified SAX polystyrene-divinyl benzene has been used for the incorporation of [l8F]fluoride into 3-acetyl-6-alpha-naltrexol triflate. Radiochemical yields are commensurate with those obtained by solution techniques (60%. EOB). The acylated radiochemical intermediate was deblocked by subsequent reaction over a second SAX polystyrene-divinyl benzene support and directly injected onto an HPLC for purification. The purified final product was isolated for formulation from HPLC eluent by extraction using a commercially available fluorocarbon membrane supported SAX resin. An automated apparatus to carry out the entire process is currently being fabricated. The techniques used will be applied to the automated preparation, reaction and isolation of other IND radiopharmaceuticals.
