Microbial challenge tests on nonradioactive TiO2-based 68Ge/68Ga generator columns.

Area of Science:

• Radiopharmaceutical chemistry
• Microbiology
• Medical device safety

Background:

• Germanium-68/Gallium-68 ((68)Ge/(68)Ga) generators are crucial for producing positron emission tomography (PET) imaging agents.
• Ensuring the sterility and safety of radiopharmaceuticals is paramount for patient well-being.
• Microbial contamination is a potential concern in the production and handling of radiolabeled compounds.

Purpose of the Study:

• To evaluate the survival and proliferation of various microorganisms within eluents and generator columns of (68)Ge/(68)Ga generators.
• To assess the impact of high microbial loads on the sterility of generator eluents.
• To determine the safety of (68)Ge/(68)Ga generator systems concerning microbial contamination.

Main Methods:

• Titanium dioxide (TiO(2)) columns from commercial (68)Ge/(68)Ga generators were inoculated with high concentrations (>10(7) CFU) of diverse microorganisms.
• Columns were eluted with 0.1 N HCl under standard conditions.
• Eluted samples were analyzed for sterility, colony-forming units (CFU), and endotoxin levels over an extended period.

Main Results:

• The eluent (0.1 N HCl) demonstrated limited initial microorganism survival.
• No survival of any tested microorganism was detected in subsequent elutions from TiO(2) generator columns, even with high initial contamination.
• Endotoxin levels remained consistently low, with no elevation observed in eluent samples.

Conclusions:

• The operational conditions within this type of (68)Ge/(68)Ga generator are highly unfavorable for microbial survival and growth.
• The risk of incidental microbial contamination during the generator's lifespan is considered very low.
• These findings support the safety profile of (68)Ge/(68)Ga generators regarding microbial contamination.