Resumo

[¹⁸F]Fludeoxyglucose (¹⁸FDG) is the most widely used radiopharmaceutical for Positron Emission Tomography (PET) in nuclear medicine. This radiopharmaceutical is produced according to Good Manufacturing Practice to ensure end-product quality. Sterility is a particularly important quality requirement, since ¹⁸FDG is intended for intravenous administration. Sterility testing of ¹⁸FDG is performed using the direct inoculation of the culture medium method, as described in F.Bras.V. Usually, compendial methods do not need to be validated; however, their suitability should be verified under actual conditions of use. In this context, the aim of this study was to evaluate the test implemented at CDTN for ¹⁸FDG sterility assessment. ¹⁸FDG was produced using a TRACERlabMXFDG synthesis module; and, it was filtered using a 0.22 µm membrane. The evaluation of the method included the assessment of bacteriostasis and fungistasis (F.Bras.V), and parameters described in U.S. Pharmacopeia as specificity, ruggedness, and repeatability. Firstly, fluid thioglycollate (TiO) and tryptic soy broth (TSB) media were inoculated with not more than 100 cfu of microorganism (Bacillus subtilis, Clostridium sporogenes, Candida albicans, Staphylococcus aureus, Aspergillus niger and Pseudomonas aeruginosa), both in the presence and in the absence of non-radioactive ¹⁸FDG. All tubes showed growth within 7 days for all microorganisms. Specificity was confirmed by adequate microbial growth of not more than 100 cfu of each strain of microorganism in TiO and TSB, incubated for not more than 3 days (bacteria) and not more than 5 days (fungi). Ruggedness was evaluated by analysis of aliquots taken from the same batch of ¹⁸FDG performed by different analysts. Results were not affected by this variable. Six samples of the same lot of ¹⁸FDG were inoculated in TiO and TSB in order to evaluate test repeatability. No microbial growth was verified in all tubes. Testing revealed no bacteriostasic or fungistasic effects of the radiopharmaceutical. Results demonstrated that the proposed method is suitable for ¹⁸FDG sterility testing at CDTN, and may be carried out without further modification.