Robotic preparation of Sodium Acetate C 11 Injection for use in clinical PET.

Sodium Acetate C 11 Injection is a radiopharmaceutical commonly used for clinical studies with positron emission tomography (PET). We have designed a fully-automated robotic system for the compounding of this 20-minute half-lived tracer in the clinical setting. The system is comprised of five modular workstations that are configured in a flexible manner to accommodate all of the steps in the production of the labeled drug. The Trapping Station isolates cyclotron-produced [11C]CO(2) gas from the target and directs carbonation of methylmagnesium Grignard in diethyl ether. The Heating Station hydrolyzes the intermediate, and removes ether and unreacted [11C]CO(2) from the mixture. The Extraction Station removes ionic and organic contaminants from the drug using solid-phase extraction (AG 11A8 and C18 resin). The Filtration Station sterilizes the radiopharmaceutical, and tests membrane patency post filtration. The Assay Station measures the weight and radioactivity content of the Final Product Container, facilitating calculation of activity concentration in a remote manner. Rapid quality control methodology has also been developed that is suitable for pre-release analysis of the drug product. For a 7.5 min irradiation with a 40 microA proton beam, 223-300 mCi of Acetate C 11 Injection with purity meeting USP standards is produced within 23 min. This robotic system is a reliable method for producing Sodium Acetate C 11 Injection, USP in the clinical setting with minimal personnel exposure. Moreover, its design flexibility permits synthesis of additional (11)C- or (18)F-labeled PET tracers within the same shielded hot cell.