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Previous issue date: 2014-02-24 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Helicobacter pylori is the main cause of gastritis, gastroduodenal ulcer disease and
gastric cancer. The most recommended treatment for eradication of this bacteria
often leads to side effects and patient poor compliance, which induce treatment
failure. Magnetic drug targeting is a very efficient method that overcomes these
drawbacks through association of the drug with a magnetic compound. Such
approach may allow such systems to be placed slowed down to a specific target area
by an external magnetic field. This work reports a study of the synthesis and
characterization of polymeric magnetic particles loaded with the currently used
antimicrobial agents for the treatment of Helicobacter pylori infections, aiming the
production of magnetic drug delivery system by oral route. Optical microscopy,
scanning electron microscopy, transmission electron microscopy, x-ray powder
diffraction, nitrogen adsorption/desorption isotherms and vibrating sample
magnetometry revealed that the magnetite particles, produced by the co-precipitation
method, consisted of a large number of aggregated nanometer-size crystallites
(about 6 nm), creating superparamagnetic micrometer with high magnetic
susceptibility particles with an average diameter of 6.8 ? 0.2 μm. Also, the polymeric
magnetic particles produced by spray drying had a core-shell structure based on
magnetite microparticles, amoxicillin and clarithromycin and coated with Eudragit?
S100. The system presented an average diameter of 14.2 ? 0.2 μm. The amount of
magnetite present in the system may be tailored by suitably controlling the
suspension used to feed the spray dryer. In the present work it was 2.9% (w/w). The
magnetic system produced may prove to be very promising for eradication of
Helicobacter pylori infections / A Helicobacter pylori ? a principal causa de gastrites, ?lceras gastroduodenais e
c?ncer g?strico. O esquema terap?utico de primeira escolha para a erradica??o
desse pat?geno leva muitas vezes a elevado n?mero de rea??es adversas, baixa
ades?o do paciente e consequentemente falha na terap?utica. A vetoriza??o
magn?tica ? uma t?cnica bastante difundida na literatura que visa minimizar esses
problemas, atrav?s da associa??o de f?rmacos a n?cleos magn?ticos direcionando
para o local de a??o por interm?dio de campo magn?tico externo. O presente
trabalho relata o estudo da s?ntese e caracteriza??o de part?culas polim?ricas
magn?ticas contendo os mais frequentes antimicrobianos (amoxicilina e
claritromicina) usados no tratamento de infec??es por Helicobacter pylori,
objetivando a produ??o de um sistema para vetoriza??o magn?tica por via oral.
Granulometria baseada no di?metro de Feret, microscopia eletr?nica de varredura e
transmiss?o, difratometria de raio-x, isotermas de adsor??o/dessor??o de nitrog?nio
e magnetometria de amostra vibrante revelaram que as part?culas de magnetita,
produzidas pelo m?todo da coprecipita??o, consistem em grande n?mero de
agregados de cristalitos de tamanhos nanom?tricos (da ordem de 6 nm) os quais
formam part?culas microm?tricas superparamagn?ticas de alta susceptibilidade
magn?tica, tendo formato irregular com di?metro m?dio de 6,8 ? 0,2 μm. Os n?cleos
magn?ticos foram revestidos por pol?mero (Eudragit? S100) em conjunto com
amoxicilina e claritromicina (forma polim?rfica II) sendo obtido micropart?culas
n?cleo-camada de formato irregular, pela t?cnica de secagem por aspers?o (spray
dryer), com um di?metro m?dio de 14,2 ? 0,2 μm. A quantidade de magnetita
presente no sistema pode ser adaptada pelo controle da suspens?o inicial usada na
alimenta??o do spray dryer. No presente trabalho o conte?do magn?tico final foi
estimado em 2,9 % (p/p). Com base nos resultados obtidos, o sistema magn?tico
produzido pode se tornar bastante promissor na erradica??o de infec??es por
Helicobacter pylori
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/18296 |
| Date | 24 February 2014 |
| Creators | Pontes, Thales Renan Ferreira |
| Contributors | CPF:33014419704, http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4787041Z8, Barbosa, Euz?bio Guimar?es, CPF:94373531153, http://lattes.cnpq.br/3197108792266393, Rebou?as, Gustavo de Oliveira Gurgel, CPF:03574307438, http://lattes.cnpq.br/1748071367144485, Carri?o, Artur da Silva |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Ci?ncias Farmac?uticas, UFRN, BR, Bioan?lises e Medicamentos |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| 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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