Automated radiosynthesis of [11C]MTP38 —a phosphodiesterase 7 imaging tracer—using [11C]hydrogen cyanide for clinical applications

We have developed 8-amino-3-(2S,5R-dimethyl-1-piperidyl)-[1,2,4]triazolo[4,3-a]pyrazine-5-[11C]carbonitrile ([11C]MTP38) as a PET tracer for the imaging of phosphodiesterase 7. For the fully automated production of [11C]MTP38 routinely and efficiently for clinical applications, we determined the radiosynthesis procedure of [11C]MTP38 using [11C]hydrogen cyanide ([11C]HCN) as a PET radiopharmaceutical. Radiosynthesis of [11C]MTP38 was performed using an automated11C-labeling synthesizer developed in-house within 40 min after the end of irradiation. [11C]MTP38 was obtained with a relatively high radiochemical yield (33 ± 5.5% based on [11C]CO2 at the end of irradiation, decay-corrected,n = 15), radiochemical purity (>97%,n = 15), and molar activity (47 ± 12 GBq/μmol at the end of synthesis,n = 15). All the results of the quality control (QC) testing for the [11C]MTP38 injection complied with our in-house QC and quality assurance specifications. We successfully automated the radiosynthesis of [11C]MTP38 for clinical applications using an11C-labeling synthesizer and sterile isolator. Taken together, this protocol provides a new radiopharmaceutical [11C]MTP38 suitable for clinical applications.

Source: Journal of Labelled Compounds and Radiopharmaceuticals - February 5, 2022 Category: Biochemistry Authors: Kazunori Kawamura, Hiroki Hashimoto, Takayuki Ohkubo, Masayuki Hanyu, Masanao Ogawa, Nobuki Nengaki, Daisuke Arashi, Yusuke Kurihara, Tomoya Fujishiro, Takahiro Togashi, Toshiyuki Sakai, Masatoshi Muto, Makoto Takei, Hideki Ishii, Takeaki Sa Tags: PRACTITIONER PROTOCOL ‐ SYNTHESIS Source Type: research