Doutorado em Ciências Farmacêuticas (FF)
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Navegando Doutorado em Ciências Farmacêuticas (FF) por Por Orientador "Gil, Eric de Souza"
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Item Eletroanálise aplicada a ensaios de compatibilidade e estabilidade de fármacos(Universidade Federal de Goiás, 2020-08-31) Carvalho, Murilo Ferreira de; Garcia, Luane Ferreira; http://lattes.cnpq.br/6624146379323596; Gil, Eric de Souza; http://lattes.cnpq.br/3218622824233303; Garcia, Luane Ferreira; Leite, Karla Carneiro de Siqueira; Alecrim, Morgana Fernandes; Marreto, Ricardo Neves; Oliveira, Thiago Levi SilvaIntroduction: The pharmaceutical industry faces a major challenge to improve the solubility of some active ingredients. Carvedilol (CRV) is the drug of therapeutic choice in cardiovascular diseases. CRV presents low water solubility and low bioavaliability. Several researches were performed in order to increase the oral bioavailability, where selfemulsifying appeared as viable alternatives. Objective: The objective of this work was to evaluate interactions between CRV and its excipients, detecting the oxidative potential of these substances, thus, providing predictive data for the oxidation that may affect the stability and bioavailability of the drug system. Methodology: In the carbon pastes preparation were used 70 mg (graphite) and 30 mg (oil). Six excipients, oleic acid, canola, capmul, safflower, sesame and Plurol isoestearique. The following proportions were used in the making of the paste: 30:0, 20:10, 15:15, 10:20 and 0:30 of liquid excipient (sample): mineral oil (mg:mg) and 1.5:68.5, 3:67 and 7:63 of solid excipient (sample): graphite (mg:mg). CRV was incorporated in the oil moiety for solubilization and after used in solidstate analysis in the carbon paste. The techniques used were cyclic voltammetry, differential pulse voltammetry and electrochemical impedance spectroscopy. Results and Discussions: The Isostearique Plurol® was found to be electro-active in the studied potential, however, this oil oxidizes in different potentials from CRV. The results show that Isostearique Plurol®, liquid excipient, isoestearique acid and the solid excipient presented the greatest variations of anodic potential and were considered the best excipients for the CRV formulation. CRV presented higher stability at room temperature (25 ºC), whereas, it presented higher stability at 50 ºC when mixed with 7% estearique acid. Conclusions: Evidences of incompatibility were not found, relative to the increase of oxidation vulnerability, when in the presence of these excipients. The employment of electroanalysis for CRV compatibility studies show promising viability.Item Preparação e uso de eletrodos de frafite nanoestruturados de vanadato de bismuto na degradação fotoeletrocatalítica de radamina B isotiacianato(Universidade Federal de Goiás, 2023-02-10) Isecke, Bruna Guimarães; Teixeira, Guilhermina Ferreira; http://lattes.cnpq.br/5992362464264556; Gil, Eric de Souza; http://lattes.cnpq.br/3218622824233303; Gil, Eric de Souza; Oliveira, Sérgio Botelho de; Colmati Júnior, Flávio; Oliveira, Mayk Teles de; Prado, Lara Barroso BritoPhotoelectrocatalysis is a promising way to treat water contaminated by negative organic compounds. The use of BiVO4 nanoparticles supported on a conductive substrate allows the degradation of pollutants to be carried out under less energetic conditions. In this work, we report the degradation of Rhodamine B Isothiocyanto dye in a BiVO4/graphite (BVO@C) electrode performed under visible light irradiation through a photoelectrocatalytic process. The BiVO4 particles passed through ultrasonic irradiation by coprecipitation and then deposited on the surface of a graphite by the impregnation method. The 23 factorial design was used to optimize electrode fabrication. The electrode was characterized using SEM/EDS, XRD and DLS techniques. For the electrochemical characterization of the electrode, cyclic voltammetry (VC) and electronic impedance spectroscopy (EIS) were performed. The evaluation of the degradation of RhB isothionate was carried out in the processes of electrooxidation and photoelectrocatalysis, controlling or not controlling the temperature using the unmodified electrode and the BVO@C electrode. The characterization of the electrode confirmed the impregnation of the graphite with a BiVO4 particle through SEM/EDS, revealing specific peaks referring to vanadium (V), bismuth (Bi) and oxygen (O). The XRD analysis bought peaks related to the monoclinic phase of BiVO4, this fact being important due to the smaller band gap value, which implies activation of the semiconductor through light in the visible range. DLS and zeta potential analysis revealed negative charges on the surface of BVO@C, PDI values that indicated that the solution used for impregnation had monodispersive characteristics, which corroborated to a less regular impregnation, since this factor does not contribute to a deposition independent. Electrochemical analyzes confirm a considerable improvement of the modified electrode through a decrease in resistivity that may be associated with the presence of BiVO4, in addition to a decrease in hysteresis in relation to the emission/reduction pair. After 30 minutes, the degradation results in the electrocatalysis (EC) and photoelectrocatalysis (PEC) system, the results were considered relevant, reaching almost 100% of the dye being degraded, with a higher degradation rate for the photoelectrocatalysis experiments in relation to electroxidation, and higher values in experiments in which temperature was not controlled. To analyze the electrode reuse cycles, several reuse cycles were performed and the electrode efficiency (BVO@C) was observed. After nine cycles of reuse of the BVO@C electrode, it was observed that it presented more than 80% of RhB efficiency. and photoelectrocatalysis of dyes from industrial effluents.Item Avaliação do potencial antioxidante e atividade vasorrelaxante de Cinnamomum sp.(Universidade Federal de Goiás, 2023-05-16) Moreno, Emily Kussmaul Gonçalves; Macêdo, Isaac Yves Lopes de; http://lattes.cnpq.br/7801802836007488; Gil, Eric de Souza; http://lattes.cnpq.br/3218622824233303; Macêdo, Isaac Yves Lopes de; Garcia, Telma Alves; Rocha, Matheus Lavorenti; Carvalho, Murilo Ferreira de; Machado, Fabio BahlsThe great interest in the study of antioxidants is mainly the prevention of physiological damage caused by oxidative processes. Cinnamon (Cinnamomum sp.), is a spice used worldwide in cooking and has gained prominence for its pharmacological properties, such as anti-inflamatory, antibacterial, antifungal, cardiovascular, among others. Given the importance of determining the antioxidant capacity in relation to therapeutic methods, this study aims to evaluate the antioxidant profile of commercial cinnamon samples by spectrophotometric, electrochemical and vasorelaxant methods. The spectrophotometric methods performed were 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2’-azinobis (3- ethylbenzothiazoline-6-sulfonic acid) (ABTS) and Folin-Ciocalteu. For the electrochemical experiments, a three-electrode system was used, consisting of carbon paste electrode, platinum wire, and Ag/AgCl/KClsat, representing the working, auxiliary, and reference electrodes, respectively. The electroanalytical methods used were differential pulse, square wave, and cyclic voltammetries. Vascular reactivity was evaluated in aortic artery rings from male Wistar rats, using arteries with intact vascular endothelium and without endothelium. The endothelial nitric oxide synthase (eNOS) pathway and the inhibitor N-nitro-L-arginine-methylester (L-NAME) were used in this analysis. The correlation between the electrochemical approach and total phenols by the ABTS, DPPH, and Folin- Ciocalceu methods were 0.63, 0.70, and 0.73, respectively, with 1 being an ideal correlation. The correlation between spectrophotometric methods was 0.83. For the electrochemical results, a similar profile was observed, with anodic peak a.c Epa1= 0.1 V, indicative of polyphenolic compounds with high antioxidant power. In addition, a biosensor on a carbon paste electrode was applied to the selected extracts using laccase enzyme, obtained by the fungus Marasmiellus sp. and a signal improvement of up to 4 times in the antioxidant profile was observed when compared to the electrode without modification. The samples were analyzed by mass spectrometer, and the main chemical markers found were coumarin, cinnamaldehyde, and eugenol. Pharmacological assays showed that these samples also promoted a significant vasorelaxant effect associated to the antioxidant potential. Thus, cinnamon showed a high antioxidant capacity, in agreement with the results obtained in other studies, emphasizing its importance as a functional food.Item Imunossensor impedimétrico para determinação de rituximabe aplicado ao controle qualidade e monitoramento clínico(Universidade Federal de Goiás, 2023-02-10) Rodrigues, Edson Silvio Batista; Neves, Bruno Júnior; http://lattes.cnpq.br/7256565904920282; Gil, Eric de Souza; http://lattes.cnpq.br/3218622824233303; Gil, Eric de Souza; Sgobbi, Lívia Flório; Feres, Valeria Christina De Rezende; Oliveira Neto, Jerônimo Raimundo de; Ferreira Júnior, ÁlvaroIntroduction: Cancer is an umbrella term for a large group of diseases that can affect any part of the body. Rituximab (RTX) is a chimeric monoclonal antibody (mAb) formed by the mouse/human combination, which specifically binds to the CD20 cell marker that is expressed in normal and malignant B lymphocytes, exerting significant antitumor activity. In this context, RTX emerged as a therapeutic alternative in the treatment of various pathologies, including autoimmune diseases, inflammatory diseases and various types of cancer in which sensitive and low-cost methods are required for therapeutic drug monitoring (TDM) and quality control (QC) of this drug. Objectives: To develop a selective electrochemical immunosensor for the detection and quantification of RTX in urine and blood. Methodology: The ploliconal antibody (pAb) was purified from chicken egg, used as a biorecognition element to create an immunosensor for the detection and quantification of RTX. The immunosensor was constructed from the immobilization of the RTX IgY antibody on the glassy carbon electrode surfaces. The characterization of the immunosensor was obtained through monitoring at each stage via cyclic voltammetry and electrochemical impedance spectroscopy, where selectivity is obtained by specifically binding pAb and RTX and casein is used to block possible nonspecific interactions of other proteins. After the development of the immunosensor, the validation of the method was carried out, evaluating the selectivity, accuracy, precision, linearity and limits of detection (LOD) and quantification (LOQ). Finally, the RTX was determined in urine and blood samples. Results and discussion: Linearity was demonstrated between charge transfer resistance and RTX from 2 to 14 μg mL−1 (r2 of 0.99), with LOD and LOQ of 130 and 400 ng mL−1 respectively. The method showed adequate precision with a RPD of 0.96% for researcher 1 and 1.27% for researcher 2, and accuracy with a RPD of 1.30%, with a confidence interval between 99.0% and 101.0 %. Selectivity was achieved by demonstrating the binding specificity between the antibody and RTX, where casein blocks non-specific binding when the immunosensor is applied to blood and urine samples. Conclusion: The developed immunosensor presented precision and accuracy for the detection of RTX with results in approximately 20 minutes. In this way, low-cost, marker-sensitive electrochemical immunosensors can help in TDM, QC and extended stability monitoring of different drugs, in a simple way and with versatile assays.