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1.
An Acad Bras Cienc ; 94(suppl 3): e20211321, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36417607

RESUMO

The concern about the risks of viral infections transmission through blood transfusion has led into a search for improvements on screening tests used for the selection of blood donors. Molecular biology techniques applied in researches of viral genomes, known as Nucleic Acid-amplification-Test (NAT), represent a technology capable of increasing transfusion safety by shortening the diagnostic window period. In Brazil, the implementation of this technology for the detection of HIV, HCV and HBV occurred due to the implantation of the NAT Kit - produced by Immunobiological Technology Institute (Biomanguinhos-FIOCRUZ), in the Brazilian blood centers. The National Health Surveillance Agency attaches great importance to validation, since it standardizes, disciplines and regulates criteria for the registration of health products. This work aims to establish a protocol of performance validation by real-time PCR method, taking as the object of study the Bio-Manguinhos NAT Kit, in order to update the product registration or to meet any future needs to ensure all regulatory requirements for the performance validation of the real-time PCR diagnostic kit. The protocol developed followed the ICH recommendations. The results revealed that the adopted methodology contemplates the necessary requirements for compliance with the Brazilian legislation, as well as the established validation parameters.


Assuntos
Infecções por HIV , Hepatite C , Ácidos Nucleicos , Humanos , Hepacivirus/genética , Vírus da Hepatite B/genética , Hepatite C/diagnóstico , Hepatite C/epidemiologia , Infecções por HIV/diagnóstico , HIV
2.
An Acad Bras Cienc ; 92(2): e20191445, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785428

RESUMO

Sildenafil is a potent selective inhibitor of phosphosdiesterase-5 previously used in erectile dysfunction and subsequently approved in 2005 for pulmonary arterial hypertension treatment. Since oral administration of sildenafil shows pharmacokinetic problems with mean absolute bioavailability of 41%, the goal of this work was to develop a novel sildenafil self-emulsifying drug delivery system (SEDDS) for oral absorption improvement and management of dosage. One pharmaceutical solution and four SEDDS containing sildenafil were successfully obtained and SEDDS formed O/W nanoemulsion with droplet size less than 300 nm. The stability studies evidenced that the SEDDS containing 3.3% w/w of sildenafil yielded the best results. The safety of 2-pyrrolidone/isobutanol in oral formulations was assessed in mice and no lethality was achieved in the placebo groups with LD50 of 490 mg/Kg for SEDDS II-3.3, suggesting it as a safe excipient for humans. Therewithal, in silico studies using PBPK models provided the pharmacokinetic profile of sildenafil SEDDS. Subsequently, in silico evaluation indicated that the sildenafil SEDDS droplet size influenced its bioavailability, enhancing absorption, assuring a good pharmacokinetic profile. These findings suggest that the formulations developed here presented the potential to enhance drug oral absorption with the possibility to control drug dosage as they are liquid pharmaceutical formulations.


Assuntos
Hipertensão Arterial Pulmonar , Animais , Química Farmacêutica , Sistemas de Liberação de Medicamentos , Emulsões , Humanos , Camundongos , Citrato de Sildenafila
3.
An Acad Bras Cienc ; 92(1): e20190336, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32321026

RESUMO

Uncaria tomentosa (UT) extracts have been shown to have promising anti-tumor activity. We hypothesized that its incorporation into nanostructured systems could improve the anticancer properties. Here, poly-e-caprolactone (PCL) and poly-d,l-lactide-co-glycolide (PLGA) were employed to generate nanoparticles loaded with UT extract in a single emulsion solvent evaporation method. The nanoparticles were characterized by particle size, zeta potential, morphology and entrapment efficiency along with stability and release profiles. The nanoparticles presented entrapment efficiencies above 60% and a mean diameter below 300nm. UT-PCL nanoparticles presented higher entrapment efficiency and mean particle size as well as a slow release rate. The UT-PLGA nanoparticles showed higher drug loading. Two prostate cancer cell-lines, LNCaP and DU145 that were derived from metastatic sites, served as model systems to assess cytotoxicity and anti-cancer activity. In vitro, both formulations reduced the viability of DU145 and LNCaP cells. Yet, the UT-PLGA nanoparticles showed higher cytotoxicity towards DU145 cells while the UTPCL against LNCaP cells. The results confirm that the incorporation of UT into nanoparticles could enhance its anti-cancer activities that can offer a viable alternative for the treatment of prostrate canner and highlights the potential of nanostructured systems to provide a promising methodology to enhance the activity of natural extracts.


Assuntos
Antineoplásicos/farmacologia , Unha-de-Gato/química , Extratos Vegetais/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Portadores de Fármacos , Humanos , Nanopartículas
4.
An Acad Bras Cienc ; 90(3): 3063-3073, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30043910

RESUMO

Dietary supplements in many countries such as the USA do not require registration prior to commercialization. The Agência Nacional de Vigilância Sanitária (ANVISA) registers substances with functional properties as foods. Lutein is a carotenoid with antioxidant activity available on the market. However, no regulatory mandates exist to govern the design of quality control tests, which are necessary to ensure formulation effectiveness. Therefore, in the present study, tablet and dosage formulations from different manufacturers were tested following general methods outlined in the Brazilian and American Pharmacopeias. The averageweight, disintegration, content and dose uniformity assays were performed for all tablets and capsules, whereas hardness assays were only performed on tablets. None of the 10 formulations studied were found to be of satisfactory quality. Of all tablets tested, two had no-significant available lutein content, which may indicate adulteration. The capsules displayed adequate amounts of lutein, however had alarmingly negative disintegration and dissolution test results, which may contribute to non-bioavailability of lutein. All formulations analyzed are currently being marketed in the Brazilian and American markets. The low physicochemical performance in these formulations can be explained by the lack of specific regulations, which are necessary to ensure the quality of lutein-containing products on the market.


Assuntos
Cápsulas/normas , Suplementos Nutricionais/normas , Regulamentação Governamental , Luteína/normas , Comprimidos/normas , Disponibilidade Biológica , Brasil , Cápsulas/química , Fenômenos Químicos , Suplementos Nutricionais/análise , Humanos , Luteína/química , Permeabilidade , Solubilidade , Comprimidos/química
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