Usawadee SakulkuOnanong NuchuchuaNapaporn UawongyartSatit PuttipipatkhachornApinan SoottitantawatUracha RuktanonchaiThailand National Science and Technology Development AgencyThe Institute of Traditional Thai MedicineMahidol UniversityThammasat University2018-09-132018-09-132009-05-08International Journal of Pharmaceutics. Vol.372, No.1-2 (2009), 105-111037851732-s2.0-64549152449https://repository.li.mahidol.ac.th/handle/123456789/28322Encapsulated citronella oil nanoemulsion prepared by high pressure homogenization at varying amounts of surfactant and glycerol, was studied in terms of the droplet size, stability, release characteristics and in vivo mosquito protection. Transparent nanoemulsion can be obtained at optimal concentration of 2.5% surfactant and 100% glycerol. Physical appearance and the stability of the emulsion were greatly improved through an addition of glycerol, owing to its co-solvent and highly viscous property. The increasing emulsion droplet increased the oil retention. The release behavior could be attributed to the effect of droplet size and concentrations of surfactant and glycerol. By fitting to Higuchi's equation, an increase in glycerol and surfactant concentrations resulted in slow release of the oil. The release rate related well to the protection time where a decrease in release rate can prolong mosquito protection time. © 2008 Elsevier B.V. All rights reserved.Mahidol UniversityPharmacology, Toxicology and PharmaceuticsArticleSCOPUS10.1016/j.ijpharm.2008.12.029