Improving abamectin bioavailability via nanosuspension constructed by wet milling technique

Poorly water-soluble and photosensitive pesticide compounds are difficult to be formulated as environmentally friendly formulations with high efficacy. Conventional wettable powder, emulsifiable concentrate and emulsion in water have disadvantages of dust drift, overuse of organic solvent and low efficacy. Therefore, there is an urgent need to construct a novel formulation to improve the bioavailability of pesticides.

An abamectin nanosuspension was developed using a wet-milling method combined with orthogonal experimental design. The average particle sizes of the abamectin nanosuspension measured by dynamic light scattering, scanning electron microscope and transmission electron microscope were 233, 90 and 140 nm, respectively. The zeta potential and sliding angle on cabbage leaves were -36.9 mV and 62°. Retention and anti-photolysis were around 1.5 and 1.6 times those of emulsions in water. Furthermore, the biological activity of the nanosuspension towards diamondback moths was approximately twice that of conventional formulations.

This study provides an easy and scalable technique for constructing pesticide nanosuspensions. The preparation and composition of the nanosuspension avoid the use of organic solvents. Application of the highly effective nanoformulation will significantly enhance pesticide efficacy, and reduce the dosage and environmental pollution of the pesticide. © 2019 Society of Chemical Industry.