Preparation and characterization of a novel controlled‐release nano‐delivery system loaded with pyraclostrobin via high‐pressure homogenization

Abstract

BACKGROUNDThe development of efficient and safe green pesticides is a scientific strategy to alleviate current pesticide residues, environmental pollution, and threats to non‐target organisms. Pesticide controlled‐release formulations (CRFs) have attracted wide attention because they can control the rate of release of active ingredients and prolong the effective duration. In particular, nanoscale pesticide sustained‐release systems have excellent biological activity and distribution performance because of their small particle size. Some technical difficulties remain in obtaining nanoscale CRFs.RESULTSWe successfully fabricated pyraclostrobin nanosphere CRF by combining high‐pressure homogenization technology and emulsion–solvent evaporation methods. The pyraclostrobin nanospheres had a uniform spherical shape with a mean particle size of 450 nm and polydispersity index of less than 0.3. The pyraclostrobin loading capacity reached 53.6%, with excellent storage stability. The contact angle of nanospheres on cucumber leaf surfaces demonstrated that it had good wettability. Compared with pyraclostrobin technical and commercial formulations, the nanosphere systems showed a significantly sustained release of pyraclostrobin for longer (up to 250 h). A preliminary bioassay against Penicillium ochrochloron showed that the bioactivity and long‐term efficiency of pyraclostrobin nanospheres were superior to those of the commercial formulation.CONCLUSIONThis research introduced a simple, fast, expandable method for preparing pyraclostrobin nanospheres. The results showed that pyraclostrobin nanospheres could prolong the duration of pesticide efficacy and enhance bioactivity. Furthermore, this technology provides a platform for scale‐up production of nano‐scale pesticide CRFs. © 2020 Society of Chemical Industry

Advances in Controlled-Release Pesticide Formulations with Improved Efficacy and Targetability

“…Additionally, some studies show that repeated application of active ingredients can result in reduced efficacy. − It was estimated that the efficiency of pesticide use in China was less than 40% in 2018 . In turn this has the potential to cause serious environmental problems, such as atmospheric, water, and soil pollution, and chronic toxicity to nontarget organisms. − Use of controlled-release formulations has the potential to improve efficacy. − …”

Fe3O4 Magnetic Cores Coated with Metal–Organic Framework Shells as Collectable Composite Nanoparticle Vehicles for Sustained Release of the Pesticide Imidacloprid

“…V Mic (cm 3 A. craccivora Koch, a typical agricultural pest against leguminous forage, was selected as a model pest to evaluate the insecticidal activity of IMI@Fe 3 O 4 @PDA@UiO-66. Blank Fe 3 O 4 @PDA@UiO-66, with the mass corresponding to the highest concentration group of IMI@Fe 3 O 4 @PDA@UiO-66, was found to show negligible toxicity toward A. craccivora Koch.…”

“…Pesticides have greatly contributed to pest control and crop yield in human history. However, about 90% of pesticides are usually lost or decomposed due to their photolysis, volatilization, leaching, and off-targeting, resulting in the overuse of pesticides, which ultimately poses a huge threat toward the environment and ecological and human health. , Therefore, the development of a nanopesticide delivery system has drawn abundant attention in terms of its prolonged effective release duration, reduced initial burst release, and decreased pesticide dosage. − Pesticide loaded into nanoparticles often exhibits improved bioactivity due to its more uniform spraying over the leaves, easier breakdown of water protection barriers, and increased affinity of pesticides to the targets, compared with traditional formulations . Up to date, a plethora of pesticide delivery systems have been developed with the help of various materials, including mesoporous silica, , clay mineral, carbon nanomaterials, , protein, synthetic polymers, and so on.…”

Enhancing Stability and Formulation Capability of Fungicides by Cocrystallization through a Novel Multistep Slurry Conversion Process

“…3,4 Pyraclostrobin (ZJ) is a strobilurin fungicide with outstanding potency and high activity that has protective and curative effects on over 150 crops. 5 The poor thermal stability of ZJ and FZ (melting at 55−72 °C, 53 °C, respectively) increases the difficulty of preparing a suspension concentrate (SC), since the grinding apparatus will get stuck during grinding as a result of the tackiness of the substance. 6,7 Most commercially available formulations of ZJ and FZ are an emulsifiable concentrate (EC) like other low-melting-point agrochemicals.…”

“…Fungal diseases are major threats to the most important crops upon which humanity depends, causing up to 30% crop losses or even higher in developing countries. , Flusilazole (FZ), a systemic fungicide, is a currently widely used antifungal in agriculture owing to its high efficacies against a broad spectrum of fungal pathogens. , Pyraclostrobin (ZJ) is a strobilurin fungicide with outstanding potency and high activity that has protective and curative effects on over 150 crops . The poor thermal stability of ZJ and FZ (melting at 55–72 °C, 53 °C, respectively) increases the difficulty of preparing a suspension concentrate (SC), since the grinding apparatus will get stuck during grinding as a result of the tackiness of the substance. , Most commercially available formulations of ZJ and FZ are an emulsifiable concentrate (EC) like other low-melting-point agrochemicals .…”