Development of a Fully Automated Low Pressure [11C]CO Carbonylation Apparatus

[11 C]Carbon monoxide ([11 C]CO) is a versatile synthon for radiolabeling of druglike molecules for imaging studies with positron emission tomography (PET). We here report the development of a novel, user-friendly, fully automated and good manufacturing practice compliant low pressure synthesis module for 11 C-carbonylation reactions using [11 C]CO. In this synthesis module, [11 C]CO was reliably prepared from cyclotron produced [11 C]carbon dioxide ([11 C]CO2 ) by reduction over heated Molybdenum and delivered to the reaction vessel within 7 min after end of bombardment, with an overall radiochemical yield (RCY) of 71 %. [11 C]AZ13198083, a histamine-type-3 receptor ligand, was used as a model compound to assess the functionality of the radiochemistry module. At full batch production conditions (55μA, 30 min), our newly developed low pressure 11 C-carbonylation apparatus enabled us to prepare [11 C]AZ13198083 in an isolated radioactivity of 8540±1400 MBq (n = 3). The radiochemical purity of each of the final formulated batches exceeded 99% and all other quality control tests results conformed with specifications typically set for carbon-11 labeled radiopharmaceuticals. In conclusion, this novel radiochemistry system offers a convenient GMP-compliant production drugs and radioligands for imaging studies in human subjects.