title: Development and characterization of micellar systems for application as insect repellents.
abstract: N,N-diethyl-meta-toluamide (DEET) is a widely used insect repellent due to its high efficacy. In this work, micellar systems based on poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer were developed and studied for the purpose of controlling the release and cutaneous permeation of DEET, using concentrated solutions of the copolymer Pluronic F127 to form thermoreversible gels. The formulations presented thermoreversible gelation above 5°C and altered rheological behavior at 15 and 25°C. The presence of the drug drastically changed the sol-gel transition temperatures. The micrographs suggest that DEET induced the formation of anisotropic structures, and Maltese Crosses were observed. The formulation containing 10wt% DEET and 15wt% Pluronic F127 presented sustained drug release for up to 7h. DEET release profile followed the Higuchi kinetics model. There was a reduction of approximately 35% in the amount of DEET absorbed through the skin after 6h. About 62% of DEET from the formulation consisting of Pluronic F127 and DEET remain retained on the skin. The anisotropic structure may constitute a barrier to diffusion and thereby controlling the drug release effectively. These tests suggest that the tested samples exhibit safety profile greater than some commercially available products.
authors.affiliation: Instituto de Macromoléculas Professora Eloisa Mano, Universidade Federal do Rio de Janeiro (IMA/UFRJ), Centro de Tecnologia, Bl. J, Avenida Horácio Macedo, 2030, Cidade Universitária, Ilha do Fundão, Rio de Janeiro CEP: 21941-598, Brazil. thaisbarradas@ima.ufrj.br
authors.forename: Thaís Nogueira
authors.initials: TN
authors.lastname: Barradas
authors.forename: Lea Maria Almeida
authors.initials: LM
authors.lastname: Lopes
authors.forename: Eduardo
authors.initials: E
authors.lastname: Ricci-Júnior
authors.forename: Kattya Gyselle
authors.initials: KG
authors.lastname: de Holanda E Silva
authors.forename: Claudia Regina Elias
authors.initials: CR
authors.lastname: Mansur
mesh_terms: D000818:Animals; D003671:DEET / Q000737:chemistry* / Q000378:metabolism; D003692:Delayed-Action Preparations / Q000737:chemistry; D066298:In Vitro Techniques; D007302:Insect Repellents / Q000737:chemistry* / Q000378:metabolism; D051379:Mice; D008823:Micelles; D020442:Poloxamer / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry* / Q000378:metabolism; D011409:Propylene Glycols / Q000737:chemistry* / Q000378:metabolism; D012212:Rheology; D012867:Skin / Q000378:metabolism; D012869:Skin Absorption; D012995:Solubility
chemical_list: D003692:Delayed-Action Preparations; D007302:Insect Repellents; D008823:Micelles; C116176:PEO-PPO-PEO; D011409:Propylene Glycols; D020442:Poloxamer; D003671:DEET; D011092:Polyethylene Glycols
keywords: DEET; Drug release systems; Insect repellent; Liquid crystals; Pluronic F127