Título: | DEVELOPMENT OF OIL-IN-WATER EMULSIONS STABILIZED BY SUSTAINABLE MATERIALS FOR CONTROLLED RELEASE OF N, N -DIETHYL-3- METHYLBENZAMIDE (DEET) | ||||||||||||
Autor: |
LUIS MIGUEL GUTIERREZ BELENO |
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Colaborador(es): |
AURORA PEREZ GRAMATGES - Orientador KAREN J. EDLER - Coorientador |
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Catalogação: | 27/JUN/2024 | Língua(s): | ENGLISH - UNITED STATES |
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Tipo: | TEXT | Subtipo: | THESIS | ||||||||||
Notas: |
[pt] Todos os dados constantes dos documentos são de inteira responsabilidade de seus autores. Os dados utilizados nas descrições dos documentos estão em conformidade com os sistemas da administração da PUC-Rio. [en] All data contained in the documents are the sole responsibility of the authors. The data used in the descriptions of the documents are in conformity with the systems of the administration of PUC-Rio. |
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Referência(s): |
[pt] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=67141&idi=1 [en] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=67141&idi=2 |
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DOI: | https://doi.org/10.17771/PUCRio.acad.67141 | ||||||||||||
Resumo: | |||||||||||||
Mosquitoes are the main vectors of transmission of diseases such as zika, dengue and
chikungunya, causing more than 700,000 cases per year. The use of repellents, mainly
topical formulations, is one of the best protective measures to reduce and/or prevent
the transmission of many insect-borne diseases. In this work, we formulated DEET/oil-in-water emulsions for the controlled release of repellents as a strategy to develop
repellent formulations with a protection time greater than 6 h. We investigated the
effects of the HLB value on the stability and viscosity of the emulsions, using a blend
of surfactants (Span 80 and Tween 80) to formulate emulsions in an HLB range
between 4-14. We also evaluated droplet size, rheological behavior, mixing method
and emulsion stability index. The developed DEET-oil-in-water emulsions containing
N, N-diethyl-3-methylbenzamide (DEET) were stabilized using two positively and
negative charged nanomaterials, silica nanoparticles (SiNP) and cationic cellulose
nanofibrils (CCNF), and a blend of food-grade nonionic surfactants to prevent
precipitation by electrostatic aggregation. The results indicate that at HLB 10, this
mixture can stabilize the emulsions regardless of the type of oil (mineral or vegetable),
and the emulsions present Newtonian behavior regardless of the mixing method. The
formulations were stable for more than four months at room temperature, showing to
be strongly resistant to destabilization by centrifugal and thermal stress when using
nanomaterials in combination with surfactants. The CCNF and SiNP kept the droplet
size distribution stable due to the increase in the viscosity of the continuous phase. The
combined action of these materials in stabilizing the DEET-containing oil phase
significantly decreased the rate of active compound release compared to non-emulsified DEET, producing a sustained release of DEET within the first 6 h.
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