Optimization and characterization of the formation of oil-in-water diazinon nanoemulsions: Modeling and influence of the oil phase, surfactant and sonication

Abstract

Nanoemulsions are particularly suitable as a platform in the development of delivery systems for lipophilic functional agents. Current research describes the formation of oil-in-water (O/W) diazinon nanoemulsions using synthetic and natural additives by adopting a high-energy (ultrasound) emulsification method. The diazinon nanoemulsions were spontaneously formed by adding dropwise a mixture of diazinon, solvent and co-solvent in an aqueous solution containing a surfactant (tween or lecithin) with continuous stirring. The nanoemulsions were then formed by ultra-sonication. The effects of three levels of active ingredient, solvent, co-solvent, surfactant, sonication time and sonication cycle and power were performed by Minitab software to design the experiment. Effects of these factors on droplet size, polydispersity index (PDI), viscosity and pH of nanoemulsions were investigated. The results of the modeling showed that the experimental data could be adequately adapted in a second-order polynomial model with a multiple regression coefficient r of 0.821 for the prediction of particle size, PDI and viscosity. The long-term and thermodynamic stability of the prepared nanoemulsions were tested. The droplet size and morphology of the nanoemulsions were measured by dynamic light scattering (DLS) and transmission electron microscopy (TEM). On this basis, a water-insoluble insecticide diazinon was incorporated into 26 optimized nanoemulsion systems to demonstrate potential applications in pest control. The results of DLS and TEM measurements showed that most of prepared nanoemulsions had an almost monodisperse droplet size distribution (PDI < 200 nm). Incorporation of diazinon had no significant effect on the size and stability of the nanoemulsions and the formulated nanoemulsion remained stable after four months of storage.

Synthesis and Technology of Nanoemulsion-Based Pesticide Formulation

“…A microemulsion based on norcantharidin [140] and emamectin benzoate [19] has been formulated to control diamondback moth. Other nanoemulsions have been developed to containing organophosphorus and pyrethroid insecticides, and they also have shown a better effect than their counterparts, free insecticides [97,141]. The incorporation of herbicides in nanoemulsion systems is expected to enhance the penetration of herbicides into plant tissue, thus facilitating good weed control with low herbicide dosage.…”

“…A microemulsion based on norcantharidin [ 140 ] and emamectin benzoate [ 19 ] has been formulated to control diamondback moth. Other nanoemulsions have been developed to containing organophosphorus and pyrethroid insecticides, and they also have shown a better effect than their counterparts, free insecticides [ 97 , 141 ].…”

A comparison of microfluidization and sonication to obtain lemongrass submicron emulsions. Effect of diutan gum concentration as stabilizer

“…An increase of ultrasonic power or amplitude applied is directly related to the reduction of the droplet size since high amplitudes generates strong shear forces. This technique has been previously used in the production of nanoemulsions formulated with triglycerides, diazino or mucilage [9][10][11] .…”

Comparative Fungicidal Activity of some Pure and Nanoemulsion Monoterpenes Effects on Soil Borne Plant Pathogenic Fungi

“…Five monoterpenes, geraniol (98%), cinnamaldehyde (98%), pulegone (92%) were obtained from Acros Organics Company (USA), while, (R)-carvone (98%), and citral (95%) from Sigma-Aldrich Chemical Co., Steinheim, Germany Figure ( Nanoemulsions were firstly prepared by stirring monoterpene, solvent, surfactant and deionized water and then further emulsification using a high-energy ultrasonic process ( Figure 2), under optimal conditions as it described by (Badawy et al 2017).The mixed monoterpenes, solvent (DMSO), surfactant (tween80) and deionized water concentration were incorporated by 5%, 5%, 10% and 80%, respectively, thus the final oil concentration was 5000 ppm. NEs of R-carvone, cinnamaldehyde, citral, geraniol and pulegone have droplet size of 67.23, 128.07, 56.64, 176.00 and 58.83 nm orderly, while, PDI values were 0.177, 0.322, 0.130, 0.630 and 0.311 respectively, (Abdelrasoul et al 2018).These nanoemulsions were immediately used for in vivo and in vitro biological assay.…”