Preparation and Characterization of Size-Controlled Nanoparticles for High-Loading λ-Cyhalothrin Delivery through Flash Nanoprecipitation

Abstract

Environmental concerns and low efficacy pose a challenge for the application of traditional insecticide formulations. In this study, a series of λ-cyhalothrin (LC)-loaded nanoparticles (NPs) were produced by flash nanoprecipitation (FNP), and the parameters that influence nanoparticle size were systematically studied. The narrowly distributed and size-controllable NPs formed stable suspensions in aqueous solution without organic solvents. The amphiphilic block polymer PEG-PDLLA played an important role as a drug carrier, and the encapsulation content was as high as 99%. The obtained NPs with high loading of LC exhibited toxicity comparable to those of two commercial formulations at low doses. This confirms that FNP technology is a promising and scalable method for agrochemical delivery.

Development of High‐Drug‐Loading Nanoparticles

“…“Co‐loading” herein is to describe a strategy that a drug is loaded or encapsulated during the formation of nanoparticles (Figure b). Various systems have been developed including pure drugs, drug‐polymer conjugate, drug‐silsesquioxane conjugate, MOF with drug incorporated, solid‐lipids, proteins, and polymers . Covalent binding plays an important role for those conjugated systems, while hydrophobic, electrostatic, and π‐π interactions are important for polymers, proteins, etc.…”

“…d ‐α‐Tocopheryl polyethylene glycol 1000 succinate (TPGS or Vitamin E TPGS) is a commonly used nonionic surfactant and can be used to improve the drug loading of polymer nanoparticles . Various drugs (camptothecin, ciprofloxacin, curcumin, λ‐cyhalothrin, and PTX) and polymers (pluronic F‐127, dextran sulfate, poly(lactide)‐poly(ethylene glycol) (PLA‐PEG), and poly(N‐vinylpyrrolidone)‐b‐poly(ϵ‐caprolactone)) have been used to form nanoparticles with drug loadings ranging from 20 to 80 % (Table ) . Flash nanoprecipitation, first introduced in 2003, was designed to achieve a mixing time less than the nucleation and growth time of a nanoparticle, and it is a rapid, scalable, and continuous bottom‐up approach to produce monodispersed nanoparticles with tunable particle sizes and high drug loading .…”

“…Two mixing devices, confined impinging jets mixer and multi‐inlet vortex mixer, have been extensively used for flash nanoprecipitation. 39 λ‐cyhalothrin loaded poly(ethylene glycol)‐poly(d,l‐lactide) (PEG‐PDLLA) nanoparticles were produced by flash nanoprecipitation using a multi‐inlet vortex mixer, which achieved 49.7 % drug loading and 99 % encapsulation efficiency (Figure ) . They were able to remain stable for up to half of a month during storage at both 0 and 25 °C.…”

Diverse Particle Carriers Prepared by Co‐Precipitation and Phase Separation: Formation and Applications

“…The nanoparticles formed by co‐precipitation are widely used to encapsulate cargos, such as β‐carotene, doxorubicin, paclitaxel, curcumin, insulin, DNA and so on, to solve the problems of low water solubility, poor stability, poor bioavailability and controlled release [54,55,56,57,58,59,60,61,62,63] . Lu et al.…”

“…[49] The nanoparticles formed by co-precipitation are widely used to encapsulate cargos, such as β-carotene, doxorubicin, paclitaxel, curcumin, insulin, DNA and so on, to solve the problems of low water solubility, poor stability, poor bioavailability and controlled release. [54,55,56,57,58,59,60,61,62,63] Lu et al used flash nanoprecipitation to prepare water-dispersible nanoparticles of 50-400 nm in size containing OZ439, a poor orally bioavailable but promising candidate for single-dose malaria treatment. Compared with unencapsulated drug, OZ439-loaded nanoparticles show characteristics of sustained release and the released drug concentration is several times higher, effectively improving the drug's bioavailability, as shown in Figure 3c.…”