Preparation and Characterization of Controlled-Release Avermectin/Castor Oil-Based Polyurethane Nanoemulsions

Abstract

Avermectin (AVM) is a low-toxic and high-active biopesticide, but it can be easily degraded by UV light. In this paper, biodegradable castor oil-based polyurethanes (CO-PU) are synthesized and used as carriers to fabricate a new kind of AVM/CO-PU nanoemulsion through an emulsion solvent evaporation method, and the chemical structure, colloidal property, AVM loading capacity, controlled-release behavior, foliar adhesion, and photostability of the AVM/CO-PU drug delivery systems are investigated. Results show that AVM is physically encapsulated in the CO-PU carrier nanospheres, the diameter of the AVM/CO-PU nanoparticles is <50 nm, and the AVM/CO-PU films are flat and smooth without any AVM aggregate. The drug loading capacity is up to 42.3 wt % with a high encapsulation efficiency of >85%. The release profiles indicate that the release rate is relatively high at the early stage and then slows, which can be adjusted by loaded AVM content, temperature, and pH of the release medium. The foliar pesticide retention of the AVM/CO-PU nanoemulsions is improved, and the photolysis rate of AVM in the AVM/CO-PU nanoparticles is significantly slower than that of the free AVM. A release mechanism of the AVM/CO-PU nanoemulsions is proposed, which is controlled by both diffusion and matrix erosion.

Development of an environmentally friendly nanoemulsion based on Ginkgo biloba exocarp extracts to control Plutella xylostella

“…These results indicated the insecticidal activity of GBEE was improved after encapsulated by nanoemulsion. Similarly, many results have been reported that nanoemulsion can enhance the oil solubility and the pesticides bioavailability ascribing to the small droplet size [45,46]. In contrast, similar LC 50 were obtained at 12 h regardless of the droplet size.…”

Anchoring PNIPAM on ATP Surface via hydrogen bonding and coordination for a temperature-responsive adsorption of hydrophobic drug

“…On the other hand, the use of pesticides identified with toxicity and carcinogenicity will lead to chemical persistence in agricultural products and environmental problems, though it can protect the agricultural cultivation from insects and ensure mass production of food to feed the growing population [18,19]. For example, acetamiprid [(E)-N1-[(6-chloro-3-pyridyl) methyl]-N2-cyano-N1-methylacetamidine, Fig.…”

Preparation and properties of lambda-cyhalothrin/polyurethane drug-loaded nanoemulsions

“…Aer 0.5 h of neutralization, the CO-PU prepolymer was prepared. 32 Subsequently, according to the designed formula in Table 1, certain amount of the pre-dissolved LC solution in acetone and the CO-PU prepolymer was rst mixed, and a predetermined amount of water was then charged into the system, and in situ soap-free phase inversion emulsication was conducted at 1100 rpm for 40 min. Finally, the LC/CO-PU nanoemulsions were obtained by removing acetone with vacuum rotary evaporation.…”

“…A facile and economic method was used to fabricate LC/CO-PU nanoemulsions, in which the CO-PU prepolymer with hydrophilic carboxyl groups was rst synthesized by step-growth addition polymerization (Fig. 1), 32 and then the homogeneous acetone solution of the CO-PU prepolymer and LC was dispersed in water through vigorous stirring via self-emulsication process as shown in Fig. 2.…”