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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Preparação de carreadores lipídicos nanoestruturados a partir de cera de carnaúba e óleo de pracaxi contendo dexametasona para tratamento tópico de inflamações cutâneas

DUARTE JUNIOR, Anivaldo Pereira 20 May 2016 (has links)
Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-05-25T13:40:41Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Tese_Anivaldo_Pereira_Duarte_Junior.pdf: 10191822 bytes, checksum: 646b55c8dd337a59ccd673e84bb95f92 (MD5) / Made available in DSpace on 2017-05-25T13:40:41Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Tese_Anivaldo_Pereira_Duarte_Junior.pdf: 10191822 bytes, checksum: 646b55c8dd337a59ccd673e84bb95f92 (MD5) Previous issue date: 2016-05-20 / CAPES / Carreadores lipídicos nanoestruturados (CLN) são sistemas coloidais que apresentam potencial de uso tópico. A utilização de constituintes de origem natural se apresenta como alternativa aos lipídios sintéticos, por isso a cera de carnaúba e óleo de pracaxi foram utilizados na preparação de CLN contendo dexametasona (DXM) com finalidade de tratar inflamações cutâneas. A caracterização do óleo foi realizada através da determinação da composição de ácidos graxos por cromatografia gasosa acoplada a detector de ionização de chama (CG-FID), densidade, viscosidade dinâmica e cinemática utilizando viscosímetro rotacional e EHL requerido. A elaboração de diagrama pseudoternário de fases (óleo/tensoativos/água), avaliação da mistura de cera/óleo por DSC e DRX, determinação do coeficiente de partição da DXM em óleo de pracaxi/água e a solubilidade em óleo de pracaxi também foram realizadas. A metodologia analítica por CLAE acoplada a detector UV para quantificação da DXM foi validada e um planejamento experimental fracionado seguido de composto central foi executado com objetivo de obter CLN em torno de 200nm, PDI ≤ 0,4 e maior eficiência de incorporação da DXM. O perfil e modelo cinético da liberação in vitro foi estabelecido e avaliou-se a penetração e/ou permeação cutânea in vitro da DXM em pele de orelha de porco utilizando células de difusão de Franz. O óleo de pracaxi contém 17% de ácido behênico e densidade de 0,90 −0,85g/cm3, viscosidade dinâmica de 65,75 −7,77mPa/s e cinemática de 72,99−9,09mm2/s entre 30−100℃. O EHL requerido do óleo de pracaxi foi 8,8 para Tween® 80 e Span® 60 (40:60) e o diagrama pseudoternário apresentou região de emulsão liquida leitosa com proporção de água a partir de 38% e a ocorrência de nanoemulsão (tamanho de 131,6 −258,3nm) com proporção de água de 87,5%. As misturas lipídicas apresentaram índice de cristalinidade de 71,88% e 31,93% em comparação com a cera de carnaúba. O método analítico apresentou parâmetros de validação adequados e a solubilidade da DXM em óleo de pracaxi foi de 190,16µg/mL. O log P da DXM em óleo de pracaxi/água foi de -0,4250. O CLN composto por DXM (0,15%), lipídios 10% (40% de óleo de pracaxi), tensoativos 5%, obtido com um ciclo de homogeneização e pressão de 600bar apresentou tamanho de 173,26nm, PDI 0,166 e eficiência de incorporação de DXM de 49,30%. O perfil cinético das formulações CLN-DXM e Gel DXM foi ajustado por modelo linear, com velocidades de 11,59 ± 0,49 µg/cm2/h e 2,42 ± 0,25µg/cm2/h, respectivamente. Entretanto, a formulação Gel CLNDXM apresentou perfil cinético melhor ajustado ao modelo de Higuchi, de acordo com a equação Q=15,64.t0,5 (2−12h)−18,432 (r 2 =0,9903). Os ensaios em pele não apresentaram absorção percutânea. A retenção da DXM no estrato córneo foi de 0,80 ± 0,13, 0,77± 0,15 e 0,16 ± 0,03µg/cm2 e na pele remanescente de 0,96± 0,17, 0,49± 0,18 e 0,13± 0,03 µg/cm2 para as formulações Gel CLN-DXM, Gel DXM e Creme DXM, respectivamente. A formulação Gel CLN-DXM promoveu penetração significativamente maior da DXM nas camadas profundas da pele em comparação às demais formulações, apresentando assim, possibilidade de exercer maior eficácia terapêutica da DXM. / Nanostructured lipid carriers (NLC) are colloidal systems that have potential for topical drug delivery. The use of natural lipids is an alternative to synthetic lipids and therefore carnauba wax and pracaxi oil were used to obtain dexamethasone-loaded NLC to treat skin inflammation. Pracaxi oil characterization was performed by fatty acids determination using gas chromatography coupled to a flame ionization detector (GC-FID). Density, kinematic and dynamic viscosities using a rotational viscometer and required HLB value were determined. Furthemore, pseudo ternary phase diagram (oil/surfactants/water), dispersed systems evaluation, wax/oil lipid mixture investigation by x-ray difraction and DSC, DXM partition coeficient in pracaxi oil/water and DXM solubility in pracaxi oil were determined. Analytical method for determining DXM content using HPLC coupled to an UV detector was validated. A fractional factorial and central composite designs to determine a CLN formulation with size around 200nm, PDI ≤ 0.4 and the best DXM incorporation efficiency was developed. The DXM in vitro release kinetic profile was evaluated and a kinetic model established. In vitro penetration and/or permeation in porcine ear skin using Franz diffusion cells was evaluated. Pracaxi oil contains 17% of behenic acid and presents a density, dynamic and kinematic viscosities, between 30 −100℃, of 0.90 −0.85g/cm3, 65.75−7.77mPa/s and 72.99−9.09mm2/s, respectively. Pracaxi oil required HLB was 8.8 using Tween® 80 and Span® 60 (40:60) surfactants. Pseudo ternary phase diagram presented a milky liquid emulsion region starting with 38% of water and the occurrence of nanoemulsion (size of 131.6 −258.3nm) at 87.5% of water. Lipid mixtures of pracaxi oil/carnauba wax showed crystallinity index varying from 71.88% to 31.93% comparedwithcarnaubawax.TheanalyticalmethodwassuitableforDXMdeterminations and the DXM solubility in pracaxi oil was 190.16µg/mL. The log P value of DXM in pracaxi oil/water was −0.4250. The CLN consisted of DXM 0.15%, 10% lipids (40% pracaxi oil), 5% surfactants was obtained with one homogenisation cycle and 600bar pressure, presented a particle size of 173.26nm, PDI of 0.166 and DXM encapsulation efficiency of 49.30%. The kinetic profile of CLN-DXM and DXM gel formulations was fitted by linear model, with speeds of 11.59 ± 0.49µg/cm2/hr, and 2.42± 0.25µg/cm2/hr, respectively. However, the CLN-DXM gel formulation presented kinetic profile best fitted to Higuchi model, according to the equation Q=15,64.t0,5 (2−12h)−18,432 (r 2 =0,9903). Skin penetration/permeation studies showed no percutaneous absorption. The formulations DXM-NLC/gel, DXM-gel and DXM cream showed DXM retention in stratum corneum layer of 0.80 ± 0.13, 0.77± 0.15 e 0.16± 0.03µg/cm2, and in remaining skin of 0.96± 0.17, 0.49 ± 0.18 e 0.13± 0.03µg/cm2, respectively. From these findings DXM-NLC/gel promoted significantly higher DXM penetration in deep skin in comparison with other DXM formulations, thus demonstrating a possible better DXM-NLC/gel therapeutic efficacy.
2

Antioxidační a protizánětlivé účinky bilirubinu. / Antioxidant and antiinflammatory effects of bilirubin.

Valášková, Petra January 2019 (has links)
For a long time, bilirubin (BR) has been considered a waste molecule with potential toxic effects especially on the central nervous system. Later, it was found that BR exhibited cytoprotective effects and mildly elevated BR levels showed antioxidant, anti-inflammatory and immunomodulatory properties, however, exact mechanisms of the anti-inflammatory actions of BR have not been fully understood yet. The main aim of this study was to assess the protective effects of BR using experimental in vivo and in vitro models in relation to inflammation and oxidative stress. Partial goal was to establish validated analytical method for determination of BR and lumirubin. Gunn and heterozygous rats were treated with lipopolysaccharide (LPS, 6 mg/kg, IP) or vehicle (saline). After 12 hours, blood and organs were collected for analyses of inflammatory and hepatic injury markers. Primary rat hepatocytes were treated with BR and TNF-α, HepG2 and SH-SY5Y cell lines were treated with BR and chenodeoxycholic acid. LPS-treated Gunn rats had a significantly decreased inflammatory response and hepatic injury compared to LPS- treated normobilirubinemic controls. We found different profile of leukocytes subsets and decreased systemic mRNA expressions and concentrations of IL-6, TNF-α, IL-1β and IL-10 in Gunn rats. Hepatic mRNA...

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