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Artigo IPEN-doc 31929 GMP compliant microbiological monitoring in hot cells for radiopharmaceuticals preparations
2025 - SANTOS, RODRIGO da S.; ZAPPAROLI, CARLOS L.; SANTOS, JOEL M. dos; CAETANO, GABRIELA F. da R.; CAVALCANTI, MARCELO de G. P.; ANDRADE, DELVONEI A.
Radiopharmaceuticals are produced inside specialized equipment named hot cell. The integration between cleanrooms and hot cells allows the radiopharmaceutical production to meet radiological protection and Good Manufacturing Practices (GMP) standards, as established by regulatory agencies. The installation of a hot cell in a pharmaceutical cleanroom is a complex activity that must be documented and validated through qualification protocols. This study aims to perform microbiological monitoring in a hot cell for aseptic radiopharmaceutical preparations at the IPEN radiopharmacy facilities, considering the active air, settle plates, contact plates, and indirect samples of gloves and clamps, as part of the equipment’s Operation Qualification (OQ) protocol. Microbiological monitoring was performed in five chambers of the hot cell (grade A and B). Four of the five chambers presented microbiological contamination within the limits established by the standard for all tests performed. The fifth chamber (Material Outlet) presented technical and construction limitations that prevented the active air sample test from being performed, so the hot cell partially met the regulatory requirements. Complementary tests, such as air cleaning by concentration of non-viable particles, detection of leaks in filtration systems, and air flow testing will contribute to justify the classification of the Material Outlet chamber.
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Artigo IPEN-doc 31928 Flowability of NbC-based cermets for additive manufacturing via L-PBF
2025 - CONDOTTA, RODRIGO; MIRANDA, FABIO; PEREIRA, NATHALIA M. G.; SANTOS, MARCELO O. dos; RODRIGUES, DANIEL; JANASI, SUZILENE R.; ORTEGA, FERNANDO S.; BATALHA, GILMAR F.
Niobium-based refractory alloys have attracted attention in several industrial areas, such as metalworking, steelmaking, military, and armoring applications, among others. The production of these refractory alloys using additive manufacturing techniques, specifically selective laser fusion in a powder bed (L-PBF), has been a major challenge; this is primarily due to the complex optimization of the sintering process parameters required to obtain dense parts, free of porosity or cracks, and to achieve highly homogeneous layers in the powder bed. However, the success of L-PBF is highly dependent on the physical properties of the powders used in the process. Key factors such as good flowability, reduced particle size and narrow distribution, sphericity, and density influence powder spreading, powder layer uniformity, and the final part integrity. Furthermore, properties of the composite, such as hardness, toughness, and wear resistance, can be modified by changing the cermet composition, which could also negatively impact its flowability. This work aims to evaluate the physical properties of NbC-based cermets with different compositions to better understand their influence on metallic powder flowability. Optimizing powder properties and flowability through processing parameters is crucial for L-PBF to fully harness the potential of NbC-based cermets, thereby paving the way for their broader adoption in high-performance applications.
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Artigo IPEN-doc 31927 Aplicação da irradiação por feixe de elétrons para remediação de compostos farmacêuticos na água
2025 - TOMINAGA, FLAVIO K.; SILVA, THALITA T.; LEO, PATRICIA; BORRELY, SUELI I.
Um número significativo de produtos farmacêuticos tem sido lançado no ambiente aquático. Esses compostos não são completamente removidos pelas estações de tratamento de água e esgoto. Além disso, esses contaminantes não são comumente monitorados e possuem potencial para causar efeitos adversos à saúde humana e ao meio ambiente. A irradiação por feixe de elétrons (EBI) tem sido aplicada como uma um método alternativo sustentável na gestão da água, sendo eficaz na remoção de poluentes orgânicos recalcitrantes em baixas doses. Este estudo tem como objetivo avaliar o efeito da EBI na toxicidade de quatro fármacos das classes anti-inflamatório (ácido acetilsalicílico), antidepressivo (fluoxetina), antibiótico (ciprofloxacina) e antidiabético (metformina), utilizando organismos de diferentes níveis tróficos (Daphnia similis, Vibrio fischeri e Saccharomyces cerevisiae). O espectro UV-Vis mostrou alterações em todos os perfis de curvas para os fármacos após irradiação com 2,5 kGy. Os resultados de toxicidade indicaram que os efeitos variaram conforme o organismo e o fármaco estudado. Para o ácido acetilsalicílico, foi observado aumento da toxicidade para os três organismos. Em contraste, para a fluoxetina, foi alcançada uma redução significativa da toxicidade (60%) para D. similis, enquanto não foram notadas alterações de toxicidade para a bactéria e a levedura. Em relação à metformina, os subprodutos radiolíticos foram tóxicos apenas para o microcrustáceo, possivelmente devido à presença residual de peróxido de hidrogênio. Por fim, para a ciprofloxacina, verificou-se um aumento da toxicidade em D. similis e V. fischeri, enquanto foi observada a detoxificação em S. cerevisiae. Em conclusão, este estudo demonstrou que a EBI é eficaz na remoção de fármacos e destacou a importância da utilização de diferentes organismos para uma avaliação de toxicidade mais abrangente.
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Artigo IPEN-doc 31926 Stability improvement of irradiated polymer composites by inorganic compounds
2025 - ZAHARESCU, TRAIAN; LUGAO, ADEMAR B.
The long-term usage of polymer products necessitates addressing the appropriate preservation of their low oxidation state that extends the warranty period. The addition of pertinent stabilization components into the composite formulations (synthesis and natural antioxidants, pristine and doped oxides, clays or couples of them) produces an improvement in the kinetic parameters characterizing the accelerated degradation that occurs during high-energy exposures. The competition between the material ageing and the mitigation of oxidation is controlled by the protection efficiency. In this paper, the main advantages of inorganic structures in comparison to classical organic antioxidants are emphasized. A significant improvement in stability, simultaneously associated with the enhancing of functional characteristics, the lack of migration, low cost and easy accessibility, make the reevaluation of certain fillers as stabilizers appropriate. The correlation between the functional properties and the filler nature in polymer materials may be reconsidered for the assessment of the participation capability of inorganic structures in the inhibition of oxidation by the inactivation of free radicals. The lifetimes of degradation intermediates extended by the activities of inorganic compounds are increased by means of electrical interactions involving the unpaired electrons of molecular fragments. These physical contributions are reflected in chemical stability. An essential feature for the presented inorganic options is a strong impact on the recycling technologies of polymers by radiation processing. Plastic products, including all categories of macromolecular materials, can gain an increased durability through the inorganic alternative of protection.