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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

Desenvolvimento, caracterização, avaliação da eficácia in vitro, in vivo e farmacocinética de nanopartículas de superfície modificada contendo quinina

Michels, Luana Roberta 11 March 2016 (has links)
Submitted by Marcos Anselmo (marcos.anselmo@unipampa.edu.br) on 2016-09-22T14:44:04Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Luana Michels.pdf: 1171595 bytes, checksum: b9997bd5e324e4be251a83985c506a7c (MD5) / Approved for entry into archive by Marcos Anselmo (marcos.anselmo@unipampa.edu.br) on 2016-09-22T14:44:18Z (GMT) No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Luana Michels.pdf: 1171595 bytes, checksum: b9997bd5e324e4be251a83985c506a7c (MD5) / Made available in DSpace on 2016-09-22T14:44:18Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Luana Michels.pdf: 1171595 bytes, checksum: b9997bd5e324e4be251a83985c506a7c (MD5) Previous issue date: 2016-03-11 / O aumento da resistência do Plasmodium falciparum dificulta o tratamento da malária, o que leva a utilização de doses mais elevadas dos fármacos e subsequente toxicidade. As nanopartículas com superfície modificada têm sido estudadas com a finalidade de alterar a performance in vivo dos fármacos. O objetivo do presente trabalho foi desenvolver, caracterizar e avaliar a eficácia in vitro, in vivo e a farmacocinética das nanopartículas contendo quinina (QN) com diferentes características de superfície: nanocápsulas revestidas com polissorbato 80; nanocapsulas revestidas com PEG e nanocapsulas preparadas com Eudragit®. As suspensões foram preparados pelo método de nanoprecipitação e caracterizados de acordo com o diâmetro, índice de polidispersão, pH, potencial zeta, teor, taxa de encapsulação e microscopia de força atômica. As nanopartículas que apresentaram os melhores resultados na caracterização e eficácia in vitro, foram escolhidas para a avaliação da farmacocinética e eficácia in vivo, utilizando ratos Wistar e camundongos infectados com o P. berghei. As nanocápsulas apresentaram os melhores resultados na caracterização físico-química, com diâmetro adequado, população monodispersa, potencial zeta mais distante de zero, maior taxa de encapsulação e penetração intra-eritrocitária. Houve um aumento significativo no t1/2 de eliminação de todas as nanocápsulas avaliadas em relação à QN livre. Na eficácia in vivo, as nanocápsulas catiônicas aumentaram a sobrevida em relação à salina e à QN livre, demonstrando que o fármaco incorporado na suspensão com características catiônicas pode alterar a eficácia da QN apresentando-se como uma alternativa potencial para o tratamento da malária. / The increase of Plasmodium falciparum resistance difficult the treatment of malaria, and the use of higher doses of the drug induce toxicity. The coating of nanoparticles have been studied with the purpose of improve the in vivo performance of drugs. The aim of this study was to develop, characterize and evaluate the efficacy in vitro, in vivo and pharmacokinetics of quinine (QN) loaded-nanoparticles with different surface characteristics: polysorbate 80 coated-nanocapsules; PEG coated-nanocapsules and nanocapsules prepared with Eudragit® RS 100. The suspensions were prepared by nanoprecipitation method and characterized according to the diameter, polydispersity, pH, zeta potential, content encapsulation rate and atomic force microscopy. The nanoparticles showed the best results on the characterization and in vitro efficacy were chosen for evaluating the in vivo efficacy and pharmacokinetics, using Wistar rats and mice infected with P. berghei. The nanocapsules showed the best results in the physical-chemical characterization, with appropriate diameter, monodisperse population, zeta potential distant from zero, the higher rate of encapsulation and intra-erythrocyte penetration. There was a significant increase in t1/2 of all nanocapsules evaluated in comparison to free QN. On the efficacy in vivo, cationic nanocapsules increased the survival rate compared to saline and to the free QN, demonstrating that the drug incorporated in the suspension with cationic characteristics can alter the efficacy of QN presenting as a potential alternative for the treatment of malaria.

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