Progress on pesticide nanosuspension and its preparation methods

Nanosuspensions are nano-colloidal dispersions of drug particles in crystal or amorphous state stabilized by surfactants. Nanosuspensions not only solve the problem of poor solubility, but also improve permeability, biological activity and efficacy of drug. The preparative technique nanosuspensions and its applications in the field of medicine and pesticide were reviewed. Furthermore, the storage stability and future development of nanosuspension have also been preliminarily analyed. The pesticide nanosuspensions can be produced either by top-down approach such as media milling, piston-gap homogenization and high pressure microfluidization or by bottom-up technique such as precipitation and supercritical fluid method. Top-down method is suitable for hydrophobic and oleophobic pesticide processing, and the preparation process is simple and easy to scale up. However, the media milling process suffers from the corrosion of the media, which results in the pollution of the samples and the pre-micronization of the samples is necessary for the piston-gap homogenization method. Bottom-up method has the advantages of low instrumental requirements and low energy consumption, but this method requires the pesticide to be soluable in at least one solvent. Because each method has its advantages and disadvantages, the combination of several methods has been applied in the preparation of nanosuspensions. Based on the low effective issues associated with the pesticide use, exploring the application prospect of nanosuspensions as a new type of pesticide formulation is crucial and has potential practical applications.