Coprecipitation‐based synchronous chlorantraniliprole encapsulation with chitosan: carrier–pesticide interactions and release behavior

Abstract

BACKGROUNDControlled‐release pesticide formulations have emerged as a promising approach towards sustainable pest control. Herein, an environment‐friendly formulation of insecticide chlorantraniliprole (CAP) was fabricated through a simple approach of coprecipitation‐based synchronous encapsulation by chitosan (CTS), with carrier–pesticide interaction mechanism and release behavior investigated.RESULTSThe resulting CAP/CTS controlled‐release formulation (CCF) showed a good loading content of 28.1% and a high encapsulation efficiency of 75.6%. Instrument determination in combination with molecular dynamics (MD) simulations displayed that the primary interactions between CAP and CTS were physical adsorption and complicated hydrogen (H)‐bonds, which formed dominantly between NH in amides [or nitrogen (N) in ring structures] of CAP and hydroxyl (or amino) groups of CTS, as well as oxygen (O) in CAP with hydrogen in CTS or H2O molecules. The in vitro release tests exhibited obvious pH/temperature sensitivity, with release dynamics following the first‐order or Ritger–Peppas model. As the temperature increased, the CAP release process of the Ritger–Peppas model changed from Case‐II to anomalous transport, and ultimately to a Fickian diffusion mechanism. The control effect against Plutella xylostella larvae also was evaluated by toxicity tests, where comparable efficacy of CCF to the commercial suspension concentrate was obtained.CONCLUSIONThe innovative, easy‐to‐prepare CCF can be used as a formulation with obvious pH/temperature sensitivity and good efficacy on target pests. This work contributes to the development of efficient and safe pesticide delivery systems, especially using the natural polymer materials as carriers. © 2023 Society of Chemical Industry.

Chitosan-Delivered Chlorantraniliprole for Pest Control: Preparation Optimization, Deposition Behavior, and Application Potential

“…Based on the combined results of contact angle and retention measurements, CCF has good wettability and deposition behaviors on plant leaf surfaces, which helps to improve its application efficiency and reduce environmental pollution. This finding is consistent with the good insecticidal activity of CCF against Plutella xylostellalarvae in our previous work …”

“…Overall, effective control of one species of mealybug genus Paraputo Laing has been successfully achieved through four consecutive sprayings of CCF at different time intervals, which provides a new window for the CAP application in mealybug control. Combined with the good insecticidal activity of CCF against Plutella xylostellalarvae in our previous work, it can be found that the innovative easy-to-prepare CCF not only can be used as a formulation with high efficiency and long duration on target pests within the killing spectrum but also has good potential for controlling some destructive pests outside the spectrum, which shows a new strategy for sustainable pest management.…”

“…The changes of apparent morphology were observed, and the EE of CAP in the formulation was determined by the HPLC method. 29 The experiments were repeated at least three times with the average values adopted. The stability degree of the insecticide loaded microparticles was calculated according to eq 2:…”

“…The storage stability of the CCF prepared under the optimum conditions was examined by keeping it in glass tubes at different temperatures of 0 ± 1, 25 ± 1, and 54 ± 1 °C for 7 and 14 days. The changes of apparent morphology were observed, and the EE of CAP in the formulation was determined by the HPLC method . The experiments were repeated at least three times with the average values adopted.…”

“…In our previous work, an innovative easy-to-prepare coprecipitation-based synchronous encapsulation technique has been developed to prepare the CAP controlled-release suspension, where natural polymer chitosan (CTS) was adopted as the carrier owing to its excellent fungicidal activity , as well as specific insecticidal activity against some lepidopterous insects . The obtained CAP/CTS controlled-release formulation (CCF) displayed obvious pH sensitivity, high cumulative pesticide release, and good insecticidal activity against Plutella xylostella­(Lepidoptera: Plutellidae) larvae.…”