Preparation and release properties of azoxystrobin/ polyacrylonitrile microspheres

In this study, polyacrylonitrile (PAN) was used to prepare PAN microspheres loaded with azoxystrobin by electrostatic spraying technology. The effects of working voltage and mass ratio of azoxystrobin and PAN on the morphology and properties of microspheres were investigated. The sustained-release properties of the drug-loaded microspheres were evaluated by release tests. The results show that the working voltage of the electrospinning machine is the main factor controlling the particle size of the microspheres. The particle size decreases with the increase of the voltage and the minimum size can reach 0.86 μm. While the mass ratio of azoxystrobin and PAN mainly affected the loading capacity and encapsulation efficiency of the microspheres. The loading capacity of the microspheres can reach up to 34.53%, and the encapsulation efficiency can reach up to 79.78%. In addition, the drug-loaded microsphere achieved stable release for up to 400 min in three buffer solutions with different pH, indicating its excellent sustained-release performance. Collectively, under the condition that the working voltage of the electrospinning machine is 15 kV, the working distance is 20 cm, the mass concentration of PAN solution is 2%, m(azoxystrobin) : m (PAN) = 1 : 2 and the injection speed is 1.25 mL/h, the prepared azoxystrobin/PAN microspheres exhibited good morphology and sustained-release properties. This study provides a technical approach for pesticide reduction and efficiency enhancement.