Automation of the radiosynthesis and purification procedures for [18F]Fluspidine preparation, a new radiotracer for clinical investigations in PET imaging of σ1 receptors in brain

The radiosynthesis of [18F]Fluspidine, a potent σ1 receptor imaging probe for pre-clinical/clinical studies, was implemented on a TRACERlabTM FX F-N synthesizer. [18F]2 was synthesized in 15min at 85°C starting from its tosylate precursor. Purification via semi-preparative RP-HPLC was investigated using different columns and eluent compositions and was most successful on a polar RP phase with acetonitrile/water buffered with NH4OAc. After solid phase extraction, [18F]Fluspidine was formulated and produced within 59±4min with an overall radiochemical yield of 37±8%, a radiochemical purity of 99.3±0.5% and high specific activity (176.6±52.0GBq/µmol). •[18F]Fluspidine is a promising radiotracer for PET imaging of sigma1 receptors.•A fully automated CGMP-oriented radiosynthesis of [18F]Fluspidine is described.•The purification was investigated using different semi-preparative HPLC systems.•[18F]Fluspidine was produced within 59±4min with a radiochemical yield of 37±8%.