Clinical efficacy of Sep-Pak ® assisted one pot automated synthesis of pharmaceutical grade [ 18 F]FLT using 5′-O-(benzoyl)-2,3′-anhydrothymidine precursor

An automated production of pharmaceutical grade 3′-deoxy-3′-[ 18 F]fluorothymidine ([ 18 F]FLT) with solid phase extraction (SPE) purification using 5′-O-(Benzoyl)-2,3′anhydrothymidine precursor (Benzoyl-Anhydro) poses a major challenge. Herein, an automated, one-pot, two-step, radiochemical synthesis of [ 18 F]FLT using benzoyl-anhydro precursor and subsequent optimization of SPE purification (using readily available SepPak® cartridges) while maintaining radiochemical purity, chemical purity and residual solvent levels within the specified limits has been reported. The current method yields pharmaceutical grade [ 18 F]FLT suitable for inclusion as a generic product in different pharmacopeia. The desired clinical results add support to indigenously produced Sep-Pak ® purified [ 18 F]FLT as a pharmaceutical grade diagnostic radiopharmaceutical.