Enhanced fungicidal efficacy and improved interfacial properties with the co-delivery of prothioconazole and tebuconazole using polylactic acid microspheres.

ABSTRACT

BACKGROUND: Prothioconazole (PTC) is one of the leading fungicide products worldwide. However, excessive use of PTC facilitates the development of resistance. Pesticide compounding technology plays an important role in reducing pesticide resistance. Microspherization technology for the construction of pesticide dual-loaded systems has recently provided a new direction for researching novel and efficient pesticide formulations. In this study, prothioconazole-tebuconazole@polylactic acid microspheres (PTC-TBA@PLA MS) were constructed by combining these two technologies. RESULTS: The final PTC-TBA@PLA MS were selected by an orthogonal method, which were uniformly spherical with smooth surface. The resultant drug loading (DL) and average particle size of PTC-TBA@PLA MS were 31.34% and 22.3 µm, respectively. A PTC-TBA@PLA MS suspending agent (SC) with a high suspension rate of 94.3% was prepared according to the suspension rate, dumping ability and stability. Compared with a commercial SC, the PTC-TBA@PLA MS SC had a larger cumulative release and better interfacial properties. Biological experiments showed that PTC-TBA@PLA MS SC had an obviously improved bactericidal effect than the commercial SC. CONCLUSION: The constructed PTC-TBA@PLA MS system detailed here is expected to reduce the risk of resistance and the frequency of pesticide use while enhancing fungal control. © 2023 Society of Chemical Industry.