Abstract

In this study, the essential oil (EO) from leaves of Croton linearis Jacq was extracted and characterized by GC/MS. The EO hydrophilic-lipophilic balance required (rHLB) for nanoemulsion (NE) development was determined by the Griffin' method. For evaluating the larvicidal effect against Aedes aegypti, the preparation process of NE was optimized, using a central composite design. It was also evaluated the possible toxic effect of NE in nontarget species. The leaves of C. linearis contain 1.50% of EO, enclosing 61 volatile compounds, mainly eucalyptol (26.66%). The best surfactant, oil:water ratio (4.5-5.0-91.5; % w:w:w), allows to achieve the optimal NE, using a stirring speed of 800 rpm, the addition rate of 0.5 ml/min, and a stirring time of 30 min. NE (with particle size = 163 nm) showed a larvicide effect (LC50 = 17.86 mu g/mL) more potent than the whole EO (LC50 = 64.24 mu g/mL). NE showed neither hemolytic effect nor cytotoxicity, and it was classified as a nontoxic product, according to the OECD class toxicity test (IC50 > 2000 mg/kg). This product arises in a new green bio-larvicide that could be used for mosquito control.