Sistemas nanoestruturados a base de PPG-5 CETETH-20, água e óleo essencial de Syzygium aromaticum: obtenção, caracterização e aplicação no controle larvicida do Aedes aegypti

• Ano de defesa: 2016
• Autor(a) principal: Santos, Kathlyn Pinheiro dos
• Orientador(a): Nunes, Rogéria de Souza
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Sergipe
• Programa de Pós-Graduação: Pós-Graduação em Ciências Farmacêuticas
• País: Brasil
• Palavras-chave em Português: Aedes aegypti; Essencias e óleos essenciais; Inseticidas; Cristais líquidos; Precusores de fases; Sizygum aromaticum; Alginato de sódio; Liquid Crystals; Sodium alginate; Phases precursors
• Área do conhecimento CNPq: CIENCIAS DA SAUDE::FARMACIA
• Link de acesso: https://ri.ufs.br/handle/riufs/3953

Aedes aegypti is the main vector of the dengue virus, urban yellow fever and emerging arboviruses in Brazil as zika and chikungunya. The use of chemical pesticides is still the main control mechanism vector, their overuse has led to the emergence of resistant insects besides mammalian toxicity and the environment. Essential oils such as essential oil Sizygum aromaticum (OESA) is an alternative in control of Ae. aegypti.In this context , the aim of this study was to develop and characterize nanostructured systems from the use of PPG -5 CETETH -20 ( cetyl alcohol propoxylated 5 OP ethoxylate 20 EO) , water, sodium alginate and essential oil Sizygum aromaticum ( OESA ) with potential application in larvicide control of Ae. aegypti. The systems were obtained by phase diagram composed of water, oleic acid, PPG-5 CETETH-20 (OA)in the ratio 2: 1 and OESA, and characterized by techniques polarized light microscopy (MLP), Smallangle Xray scattering(SAXS) and rheological analysis.In this diagram, we chose a liquid crystalline phase precursor to polymer incorporation of sodium alginate, to increase the physical stability of the system. Were also made in water increases precursor and then characterized by such techniques. The larvicidal activity was evaluated from the determination of the median lethal concentration (LC50) against Ae. aegypti. According to the results the main constituent of OESA was eugenol (76.75 %), oil yield was 3.66% (w / v) and density of 1,04g / ml. We observed four distinct regions of the diagram, liquid crystal (LC) emulsion (ME), microemulsion (ME) and phase separation. Through the images of MLP was observed isotropic systems as (MEs) and anisotropic systems as lamellar CLs.The SAXS measurements confirmed the structures visualized by MLP, showing broad peaks of low intensity for MEs, phase transition and the ratio between CL lamellar peaks of 1: 2: 3. The study showed that the rheological properties of the systems and MEs phase transition are Newtonians and LCs are non-Newtonian. With the aqueous phase the increased phase precursor showed a greater degree of structuring, becoming lamellar liquid crystalline systems. Confirmed through the MLP techniques to display "Maltese crosses '' SAXS with ratios of 1: 2: 3 and rheological analysis with an increase in storage modulus. After incorporating polymer, systems are presented anisotropic with lamellar system characteristics and hexagonal system having more than one set of lamellae observed in the MLP and confirmed by SAXS measurements, which showed ratios of 1: 2: 3 to lamellar CL and 1: 1.73: 2: 2.64 hexagonal CL. In rheological analysis showed an increase in independent storage modulus of the characteristic frequency of structured systems.For the larvicidal activity, A2 and F8 samples showed LC50 8.14 and 3.37 ppm, respectively, indicating the presence of the polymer contributed to a better larvicidal activity. Thereby, it can be concluded that there were obtained phase precusores with a potential use against Ae. aegypti larvae.