Optimization and Characterization of Essential oil Nanoemulsions Using Ultrasound for New Ecofriendly Insecticides

Abstract

This study developed and evaluated the toxicological effects of new stable nanoemulsions (NEs) of peppermint essential oils (EO) and palmarosa EO + linalyl acetate using ultrasound cavitation. Moreover, the study analyzed the effect of linalyl acetate in the stabilization process of palmarosa NEs. Peppermint NEs had sizes of 34 nm and polydisperse index (PDI) values of 0.424 pwhile palmarosa NEs showed sizes of 15 nm and PDI of 0.078. Peppermint NEs were stable for 30 days and palmarosa NEs, for 120 days. The insecticidal effect of NEs were also evaluated against Cx p. pipiens and P. interpunctella larvae. In Cx p. pipiens, the Cl50 values were 31.24 ppm for peppermint NEs and 32.30 ppm for palmarosa + linalyl acetate NEs. In P. interpunctella, the NEs were combined with β-cypermethrin and the CL50 values were 0.12 μg larvae-1 for peppermint NEs and 0.23 μg larvae-1 palmarosa + linalyl acetate NEs. In addition, the NEs showed not toxicity effect in non-target organisms such as A. salina and T molitor. Finally, viability on mammalian cell culture model was evaluated and also observed that NEs no affected the cell viability after 3 and 7 days of exposure.