Insecticidal nanoformulations based on a lipid matrix: Physicochemical properties and their effect on non-target aquatic biota

The incorporation of lambda-cyhalothrin (LC) in lipid nanoparticles (LN) could be a sustainable strategy to increase its efficacy and decrease its hazard to the environment. The purpose of the present work was to perform the interaction between LC and LN after nanoencapsulation and to evaluate their effect on species from different aquatic trophic levels such as Aliivibrio fischeri, Raphidocelis subcapitata, Lemna minor, and Daphnia magna. LN loaded with LC (LN-LC) were produced by green and simple methodology without organic solvents using Precirol ATO5® and Capryol 90® as solid and liquid lipids, respectively, and soy lecithin and TEGO® Care as emulsifiers. The physicochemical interaction between LC and LN was assessed by differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR), and X-ray, confirming that LC is associated with the lipid lattice of nanoparticles, characterized by an amorphous matrix. The data from biological tests showed no or low toxicity of LN-LC on the selected aquatic organisms. Thus, encapsulation in lipid-based nanoparticles may be a promising and sustainable choice for using this insecticide in agricultural practices, reducing its environmental risk.