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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

Enabling solid lipid nanoparticle drug delivery technology by investigating improved production techniques

Triplett, Michael David, II January 2004 (has links)
No description available.
2

Preparação e caracterização de micro e nanopartículas lipídicas sólidas para aplicação em cosméticos / Preparation and caracterization of solid lipid micro and nanoparticles, for application in cosmetics

Rossan, Marcos Roberto 18 August 2018 (has links)
Orientador: Maria Helena Andrade Santana / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-18T18:45:10Z (GMT). No. of bitstreams: 1 Rossan_MarcosRoberto_M.pdf: 4251170 bytes, checksum: f64611ade06535fb615dbd4f23afd20f (MD5) Previous issue date: 2011 / Resumo: Neste trabalho, estudou-se o desenvolvimento tecnológico de micro/ nanopartículas lipídicas sólidas para aplicação cosmética capilar. As micropartículas foram produzidas por spray cooling, onde incorporou-se na matriz lipídica, composta por ceras naturais de origem vegetal (cera de carnaúba), mineral (microparafina) e sintética (cera de silicone), um ativo doador de brilho capilar, de nome comercial Activeshine Amazon, composto por uma mistura de triglicerídeos de murumuru e babaçú. As micropartículas foram obtidas a partir de misturas contendo 30% das ceras, porém a incorporação total do ativo na matriz lipídica ocorreu a partir de 70% de cera. A produção das micropartículas foi estudada através de um planejamento estatístico de experimentos e analise de superfície de resposta, onde determinou-se a influência da pressão do ar de atomização e concentração da cera, sobre o diâmetro médio. Os resultados mostraram que a pressão do ar de atomização foi a principal variável de significância estatística para os três tipos de ceras. Foram obtidas micropartículas esféricas, com diâmetro entre 30 - 320 ?m. As nanopartículas foram obtidas a partir da mistura lipídica composta por 50% de Activeshine Amazon e 50% de cera de carnaúba, além de sorbitol, óleo de mamona PEG-40 e quaternários de amônio (CTAC, BTAC e SDBAC), via nano-emulsificação de baixa energia, através do processo de inversão de fase por temperatura. Foram obtidas partículas com 0,08 a 0,35 de polidispersidade, 45 - 190 nm de diâmetro médio, e -20 A +70 mV de potencial zeta. Nestes estudos, verificou-se a influência destes componentes da formulação sobre o ponto de inversão de fase, comprovado por medidas de condutividade elétrica. Estes resultados mostram que os processos de spray cooling e nano-emulsificação utilizando ceras e triglicerídios produzem micro e nanopartículas que atendem aos requisitos de diâmetro médio, polidispersidade e potencial zeta para aplicação capilar. Essas partículas são também potencialmente úteis para a encapsulação de bioativos e desenvolvimento de formulações mais eficazes comparadas às que utilizam os compostos livres / Abstract: This work studied the technological development of solid lipid micro and nanopaparticles for cosmetic hair application. The microparticles were produced through spray cooling process, in which an active donator of hair brightness, commercially named Activeshine Amanzon was incorporated. The solid lipid matrix was composed by waxes from vegetal (carnauba), mineral (microparaffin) and synthetic (silicon) origin. The Activeshine Amazon is a mixture of triglycerides from murumuru butter and babassu oil. The microparticles were obtained from admixtures containing 30% of the waxes, but the total incorporation of the active in the lipid matrix occurred from 70% only. The production of microparticles was studied through a statistical experimental planning and surface response analysis from which it was determined the influence of the inlet atomization air pressure and wax concentration on the mean diameter of the particles. The results shown the air pressure was the statistically main significant variable for the three studied waxes. The mean diameter of the obtained spherical microparticles was in the range of 30 to 320 ?m. The nanoparticles were obtained through low-energy nano-emulsification process, known as temperature phase inversion. They were composed by a mixture of 50% Activeshine Amazon and 50% of carnauba wax, in which was also added sorbitol, castor oil PEG-40 and the ammonium quaternaries CTAC, BTAC and SDBAC. They presented 0.08 to 0.35 polydispersity, 45 to 190 nm mean diameter and -20 to + 70 mV zeta potential. The visual influence of the components of the formulation on the inversion phase temperature was comproved by electrical conductivity measurements. From these results we conclude that the spray cooling and nano-emulsification processes which use triglycerides as raw materials produce nano and microparticles which to meet the mean diameter, polydispersity and zeta potential requirements for hair care application. In addition to that, the particles are potentially useful for encapsulation of bioactives and also for the development of more efficient formulations than the free compounds ones / Mestrado / Desenvolvimento de Processos Biotecnologicos / Mestre em Engenharia Química
3

Desenvolvimento de nanopart?culas lip?dicas contendo paclitaxel

Marcial, Sara Pacelli de Sousa January 2016 (has links)
?rea de concentra??o: Ci?ncias farmac?uticas. / Data de aprova??o ausente. / Disponibiliza??o do conte?do parcial, conforme Termo de Autoriza??o no trabalho. / Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2016-12-20T19:20:11Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) sara_pacelli_sousa_marcial_parcial.pdf: 166236 bytes, checksum: c01c4f087337cd82c64b06b90a1cc4dc (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2017-01-17T18:55:36Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) sara_pacelli_sousa_marcial_parcial.pdf: 166236 bytes, checksum: c01c4f087337cd82c64b06b90a1cc4dc (MD5) / Made available in DSpace on 2017-01-17T18:55:36Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) sara_pacelli_sousa_marcial_parcial.pdf: 166236 bytes, checksum: c01c4f087337cd82c64b06b90a1cc4dc (MD5) Previous issue date: 2016 / Funda??o de Amparo ? Pesquisa do Estado de Minas Gerais (FAPEMIG) / O paclitaxel (PTX) ? um agente quimioter?pico que tem uma importante fun??o no tratamento de v?rios tipos de c?ncer, especialmente o c?ncer de mama. No entanto, a baixa solubilidade do PTX em meio aquoso (coeficiente de parti??o log = 3,96) representa uma limita??o para a administra??o intravenosa. A formula??o convencional do PTX cont?m uma alta concentra??o de Cremofor-EL? (derivado polietoxilado do ?leo de r?cino), o qual induz significante toxicidade, restringindo sua utiliza??o cl?nica. A encapsula??o do PTX em sistema de libera??o de f?rmacos pode melhorar a absor??o e aumentar a sua efic?cia terap?utica. Neste estudo, tr?s diferentes nanossistemas lip?dicos contendo PTX, nanopart?culas lip?dicas s?lidas (NLS), nanoemuls?o (NE) e carreadores lip?dicos nanoestruturados (CLN) foram preparados e as propriedades f?sico-qu?micas e a atividade citotoxicidade in vitro foram avaliadas. Em rela??o ao di?metro m?dio, o CLN branco mostrou valor de di?metro aproximadamente 2 e 1,7 vezes menor que os obtidos para NLS e NE, respectivamente. A presen?a de PTX levou a um aumento significativo no di?metro das part?culas em todos os sistemas avaliados, exceto no NE. Al?m disso, o aumento da concentra??o do f?rmaco (0,01% para 0,025%) produziu um aumento do di?metro para a prepara??o de CLN. Todas as formula??es com PTX mostraram ?ndice de polidispers?o superior a 0,3, exceto para NE-PTX na concentra??o do f?rmaco igual a 0,01% (p/v). Valores negativos de potencial zeta foram observados para todas as formula??es avaliadas. CLN-PTX foi o sistema mais est?vel ap?s armazenado por 30 dias a 4 ?C. O estudo de citotoxicidade nas linhagens celulares de c?ncer de mama (MDA-MB-231 e MCF-7) demonstrou atividade citot?xica mais pronunciada para CLN-PTX do que para o PTX livre em ambos as linhagens celulares do tumor. Baseado nesses resultados, CLN-PTX parece ser uma ferramenta potencial para o tratamento do c?ncer de mama. / Disserta??o (Mestrado) ? Programa de P?s-gradua??o em Ci?ncias Farmac?uticas, Universidade Federal dos Vales do Jequitinhonha e Mucuri, [2016]. / Paclitaxel (PTX) is a chemotherapeutic agent that plays an important role in the treatment of several types of human cancer, especially breast cancer. However, the low solubility of PTX in aqueous medium (partition coefficient log of 3.96) represents a barrier for intravenous administration. The conventional PTX formulation contains a high concentration of Cremophor-EL? (polyethoxylated castor oil), which is associated with significant toxicities restricting its clinical use. The encapsulation of the PTX in drug delivery systems could improve the uptake and increase its therapeutic efficacy. In this study, three different lipid nanosystems containing PTX, solid lipid nanoparticle (SLN), nanoemulsion (NE), and nanostructured lipid carrier (NLC) were prepared, and the physicochemical properties and in vitro cytotoxic activity were evaluated. Concerning the mean diameter, NLC blank showed diameter values approximately 2 and 1.7-fold lower than those obtained for SLN and NE, respectively. The presence of PTX leads to a significant increase in the particle diameter in all systems evaluated, except NE. In addition, increases in drug concentration (0.01% to 0.025%) produced an enhanced diameter for NLC preparation. All formulations containing PTX showed PI higher than 0.3, except for NE-PTX at drug concentration equal to 0.01% (w/v). Negative zeta potential values were observed in all formulations evaluated. NLC-PTX was the system more stable after storage for 30 days at 4 oC. The cytotoxicity studies on breast cancer cell lines (MDA-MB-231 and MCF-7) demonstrated cytotoxic activity more pronounced for NCL-PTX than for free PTX for both tumor cell lines. Thus, the results showed that NCL-PTX seems to be a potential tool for the treatment of breast cancer.

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