Preparation and characterization of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) microspheres for controlled release of buprofezin

Extensive application of pesticides has caused a lot of environmental pollution and health problems, prompting the development of highly efficient and lowly toxic pesticide formulations. Here, buprofezin (BPF)-loaded poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (P(HB-HH)) microspheres were prepared by O/W emulsion/solvent evaporation method. Under optimal conditions (P(HB-HH) 7.07% ( w / v ) and PVA 1.84% ( w / v )), the spherical and monodispersed microspheres were obtained. The average particle size, pesticide loading (PL), and encapsulation efficiency (EE) of the optimized microspheres were 1.2 μm, 15.68%, and 78%, respectively. Release of 80% BPF from the microspheres in pH 5 (192 h) was faster than that in pH 7 (228 h) and 8 (204 h). Moreover, kinetic analysis indicated that BPF release behaved in a non-Fickian diffusion manner (0.43