Method for preparing controlled-release nano-pesticide preparation

Abstract

The invention provides a method for preparing a controlled-release nano-pesticide preparation. The method comprises the following steps: emulsifying components of the nano-pesticide preparation to form an initial emulsion; and then performing high-pressure homogenization to form a fine emulsion to prepare a wall-material-coated nano-pesticide preparation. The method is simple, easy to operate and good in repeatability, and the prepared nano-pesticide preparation is small in grain size, favorable in grain dispersity and excellent in controlled-release performance.

Description

technical field [0001] The invention belongs to the technical field of pesticides. Specifically, the present invention relates to a preparation method of nanopesticide preparation. Background technique [0002] Pesticides are an important material basis for ensuring national food security. Traditional pesticide dosage forms are mostly open systems. Judging from the registration of pesticide dosage forms, traditional pesticide dosage forms such as emulsifiable concentrates, wettable powders, and microemulsions account for more than 70% of the domestic market. Most of these traditional dosage forms are open. In the process of use, there are losses such as droplet rolling, drifting, bouncing, and dust drift to varying degrees. The effective utilization rate of finally reaching the crop target is less than 30%, and the amount of drug reaching the pest is less than 0.1%. The effective utilization rate is low. [0003] When pesticides are prepared into dosage forms with differe...

AI Technical Summary

Problems solved by technology

Traditional pesticide dosage forms are mostly open systems. Judging from the registration of pesticide dosage forms, traditional pesticide dosage forms such as emulsifiable concentrates, wettable powders, and microemulsions account for more than 70% of the domestic market. Most of these traditional dosage forms are open. In the process of use, there are losses such as droplet rolling, drifting, bouncing, and dust drift to varying degrees. The effective utilization rate of finally reaching the crop target is less than 30%, and the amount of drug reaching the pest is less than 0.1%. The effective utilization rate is low

When high-concentration microsphere / microcapsule preparations are prepared by interfacial polymerization, crystallization is prone to occur, and the crystallized irregular crystals will destroy the capsule wall, resulting in failure to exert drug effect

The spray drying method is a physical preparation method. The particle size of the pesticide microsphere / microcapsule preparation prepared by this method is relatively large, and it is difficult to achieve a nanometer particle size.

At present, the pesticide microsphere / microcapsule preparations prepared by traditional methods have the following defects: In terms of structure, the particle size of the currently commercially available pesticide microsphere / microcapsule preparations is generally around 5 microns, which has not reached the nanometer level, and the coarse particle size It is easy to cause droplets to roll off and dust to drift, making the adhesion, permeability and bioavailability to crop targets poor during use, and at the same time the activity is also low; in terms of particle dispersibility, the currently prepared pesticide microspheres / Microcapsule preparations have poor monodispersity, serious agglomeration, and uneven particle size distribution, and their surface properties and structural morphology have not been effectively regulated; in terms of controlled release of pesticides, the existing pesticide microspheres / microcapsules Most of the preparations can only achieve simple and qualitative slow release, and the release rate is unstable and controllable; in terms of process flow, traditional methods mostly use heating and heat preservation, gas protection and other processes, which are complicated, difficult to control and poor in repeatability

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