Fully Automated Production of 68Ga-DOTA-NOC with a Trasis miniAIO® Synthesizer

Results and conclusion Our objective was to develop a fast and reproducible fully automated method for the preparation of 68Ga-labelled DOTA-peptide with the miniAIO® synthesis module made by Trasis SA (Figure 1). The labelling of an easily commercially available peptide, DOTA-NOC, was designated as a proof of concept for this purpose. The synthesis of 68Ga-DOTA-NOC was performed on a miniAIO® synthesizer which has several advantages: using single-use cassettes (Figure 2), monitoring the radiosynthesis by means of radioactivity detectors (Figure 4) and being small and easily implantable in GMP hot cells. The leachable of metallic contaminants was taken in account for the choice of the cassette materials. The synthesis includes the following steps: • Elution of 68Ga from a 68Ge/68Ga generator with 8 mL of a HCl solution. Two different generators were tested: iThemba‘s 370 MBq eluted with 0.6N HCl and Eckert-Ziegler‘s 1850 MBq eluted with 0.1N HCl (Figure 1). • The eluate was saturated with NaCl and then passed through a strong anion exchange resin (Waters OASIS MAX) to concentrate 68GaCl4(method derived from [1]). • 68Ga was then eluted from the resin with 200 μL of physiologic liquid (NaCl 0,9%) directly into the reaction vial containing the peptide solubilized in acetate buffer. • The mixture was heated at 95°C for 7 min. • The crude reaction media was passed through a hydrophilic/lipophilic resin (Waters OASIS HLB) and the resin was rinsed with NaCl 0,9% to remove free 68Ga3+. • 68Ga-DOTA-NOC was eluted with 0.5 mL of ethanol and diluted with NaCl 0.9% and filtered with a 0.22 μm filter. The quality of the product was assessed by UHPLC with UV and radiochemical detection, GC, pH determination.