Bactericidal sustained-release microsphere and preparation method thereof

Abstract

The invention provides a bactericidal sustained-release microsphere and a preparation method thereof. According to the method, a systemic triazole compound bactericide, i.e., difenoconazole-flusilazole technical, is used as a core material, and a degradable polymer material, i.e., polylactic acid, is used as a wall material; and a solvent evaporation process is employed for preparation of the bactericidal sustained-release microsphere. The preparation method of the invention solves the problems of easy drifting, easy degradation, low utilization rate and the like of traditional pesticides; andpolylactic acid is used as a wrapping material and has the characteristics of safety, low toxicity, easy degradation, environmental safety and the like compared with traditional chemical synthetic materials such as polyurea, urea formaldehyde resin, polyurethane and polyamide. Through compounding of pesticides and preparation of the sustained-release microsphere, a prevention and treatment spectrum is broadened; pesticide efficacy is improved; environmental pollution is reduced; prevention and treatment cost is lowered; and the requirements of pollution-free agricultural production are met.

Description

Technical field [0001] The invention relates to the technical field of pesticide preparation, in particular to a bactericidal slow-release microsphere and a preparation method thereof. Background technique [0002] Pesticide formulation processing refers to adding appropriate adjuvants to the original pesticide and giving it a certain use form to improve the dispersion of active ingredients, optimize biological activity, and facilitate use. Pesticide formulation processing provides an effective way for the commercial production and large-scale promotion and application of pesticides. It is a key component of the pesticide industry and an important direction of pesticide research. [0003] Since modern times, pesticide formulation processing has developed rapidly all over the world. However, at the present stage, pesticide formulations in China are still dominated by old formulations such as emulsifiable concentrates and powders. Emulsifiable concentrates use toluene, xylene, etc....

AI Technical Summary

Problems solved by technology

[0005] At present, when preparing sustained-release agents, it is usually necessary to make the drug into the form of sustained-release microspheres, and in the commonly used preparation methods of polylactic acid microspheres, for example: the spray drying method is to dissolve the drug under the action of an atomizer. The polymer solution is dispersed into extremely small droplets, and then an inert hot gas flow is introduced to rapidly evaporate the solvent in the droplets, and the droplets shrink to form microcapsules or microspheres. This method is not suitable for temperature-sensitive drugs and the particle size of the drug is not large. Good control; another example is the melting method, which emulsifies the mixture of drug and PLA at a temperature higher than the melting point of the polymer, and then collects the microspheres by spray drying, centrifugation or freeze drying. Higher stability; or phase separation method, first emulsifying the wrapper and the polymer together to form a W / O emulsion, then adding a liquid insoluble in the polymer to the primary emulsion, the emulsion precipitates, and finally forms microspheres , and then add a large amount of non-solvent to this suspension, and finally all the organic solvents are taken away, and particles can be obtained after sieving, washing, and drying, but this method requires a large amount of organic solvent, and the obtained particles have low drug loading and relatively small particle Big

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