Mentha piperita (peppermint) essential oil nanoemulsion was prepared by low energy spontaneous emulsification method. GC-MS analysis revealed the composition of peppermint essential oil and menthol (45.2%) was the major bioactive compound along with menthone (15.39%), neomethol (8.1%), menthyl acetate (7.7%) and isomenthone (7.4%). Optimization of the nanoemulsion preparation process was done by Response Surface Methodology (RSM) with Central Composite Design (CCD). The droplet diameter and polydispersity index at optimized conditions (15% oil concentration, 25% surfactant concentration and Tween80 as surfactant) were 39.2 nm and 0.22 respectively. Optimized peppermint oil nanoemulsion (OPNE) was optically transparent, spherical in morphology and was stable for 6 months. OPNE formulation demonstrated dose, time and size-dependent larvicidal activity against malaria vectors with LC₅₀ value of 48 ppm and 123 ppm against Anopheles culicifacies and Anopheles stephensi respectively. The LC₅₀ values were 90 ppm and 163 ppm against Anopheles culicifacies and Anopheles stephensi correspondingly for the bigger droplet size formulation (PNE, droplet diameter: 129.6 nm) confirming the droplet size-dependent larvicidal activity of the nanoemulsion. The results of this study propose that peppermint oil-based nanoemulsion possibly be used as an eco-friendly larvicide for mosquito vector control strategies.

中文翻译：

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抗幼虫纳米乳剂的配方：液滴大小对印度恰蒂斯加尔邦针对疟疾媒介的幼虫活性的影响

薄荷（薄荷）精油纳米乳液是通过低能自发乳化法制备的。GC-MS分析表明，薄荷精油和薄荷醇的成分（45.2％）与薄荷酮（15.39％），新甲醇（8.1％），乙酸薄荷酯（7.7％）和异薄荷酮（7.4％）一起是主要的生物活性化合物。纳米乳液制备工艺的优化是通过具有中央复合设计（CCD）的响应表面方法（RSM）完成的。在最佳条件下（15％的油浓度，25％的表面活性剂浓度和Tween80作为表面活性剂），微滴直径和多分散指数分别为39.2 nm和0.22。优化的薄荷油纳米乳液（OPNE）光学透明，呈球形，可稳定放置6个月。OPNE配方显示剂量，_50个值分别为库蚊和斯蒂芬按蚊的48 ppm和123 ppm 。对于较大的液滴尺寸制剂（PNE，液滴直径：129.6 nm），对皱纹按蚊和斯蒂芬按蚊的LC ₅₀值分别为90 ppm和163 ppm ，确认了纳米乳剂的液滴尺寸依赖性幼虫活性。这项研究的结果表明，薄荷油基纳米乳液可作为一种生态友好的杀幼虫剂用于蚊媒控制策略。