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Previous issue date: 2013-04-05 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / This thesis was devoted to the development of innovative oral delivery systems for two
different molecules. In the first part, microparticles (MPs) based on xylan and Eudragit? S-
100 were produced and used to encapsulate 5-aminosalicylic acid for colon delivery. Xylan
was extracted from corn cobs and characterized in terms of its physicochemical, rheological
and toxicological properties. The polymeric MPs were prepared by interfacial cross-linking
polymerization and spray-drying and characterized for their morphology, mean size and
distribution, thermal stability, crystallinity, entrapment efficiency and in vitro drug release.
MPs with suitable physical characteristics and satisfactory yields were prepared by both
methods, although the spray-dried systems showed higher thermal stability. In general, spraydried
MPs would be preferable systems due to their thermal stability and absence of toxic
agents used in their preparation. However, drug loading and release need to be optimized. In
the second part of this thesis, oil-in-water microemulsions (O/W MEs) based on mediumchain
triglycerides were formulated as drug carriers and solubility enhancers for amphotericin
B (AmB). Phase diagrams were constructed using surfactant blends with hydrophiliclipophilic
balance values between 9.7 and 14.4. The drug-free and drug-loaded MEs presented
spherical non-aggregated droplets around 80 and 120 nm, respectively, and a low
polydispersity index. The incorporation of AmB was high and depended on the volume
fraction of the disperse phase. These MEs did not reduce the viability of J774.A1
macrophage-like cells for concentrations up to 25 μg/mL of AmB. Therefore, O/W MEs
based on propylene glycol esters of caprylic acid may be considered as suitable delivery
systems for AmB / Esta tese teve como objetivo o desenvolvimento de novos sistemas de libera??o para duas
mol?culas distintas. Na primeira parte, micropart?culas ? base de xilana e Eudragit? S-100
foram produzidas para encapsular ?cido 5-aminosalic?lico visando ? libera??o c?lonespec?fica.
A xilana foi extra?da de sabugos de milho e caracterizada quanto ?s suas
propriedades f?sico-qu?micas, reol?gicas e toxicol?gicas. Em seguida, dois m?todos de
microencapsula??o foram utilizados: reticula??o interfacial polim?rica e secagem por
aspers?o. Os sistemas produzidos foram caracterizados quanto ? morfologia, tamanho m?dio e
distribui??o, estabilidade t?rmica, cristalinidade, taxa de encapsula??o e libera??o do f?rmaco
in vitro. Foram obtidas micropart?culas com adequadas caracter?sticas f?sicas e rendimentos
satisfat?rios atrav?s dos dois m?todos, embora os sistemas aspergidos tenham apresentado
maior estabilidade t?rmica e sejam considerados mais interessantes devido a sua maior
estabilidade t?rmica e aus?ncia de agentes t?xicos. No entanto, ajustes precisam ser feitos
para melhorar a encapsula??o e libera??o do f?rmaco. Na segunda parte, microemuls?es do
tipo ?leo em ?gua (MEs O/A) com base em triglicer?deos de cadeia m?dia (MCT) foram
produzidas visando ao carreamento de anfotericina B (AmB) e aumento da sua solubilidade.
Foram obtidas MEs O/A sem e com AmB com got?culas em torno de 80 e 120 nm,
respectivamente, e ?ndices de polidispers?o de 0,25 e 0,31, respectivamente. A taxa de
incorpora??o da AmB foi alta e dependente do volume da fase dispersa. A viabilidade celular
n?o foi afetada at? 25 μg/mL da AmB. Portanto, MEs O/A a partir de MCT podem ser
promissores sistemas de libera??o para AmB
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/13309 |
| Date | 05 April 2013 |
| Creators | Silva, Acarilia Eduardo da |
| Contributors | CPF:38878240400, http://lattes.cnpq.br/6907806915889763, Barratt, Gillian, Saulnier, Patrick, Legrand, Philippe, Espuelas, Socorro, Egito, Eryvaldo S?crates Tabosa do |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Ci?ncias da Sa?de, UFRN, BR, Ci?ncias da Sa?de |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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