Biocompatible Nutmeg Oil-Loaded Nanoemulsion as Phyto-Repellent

Abstract

Plant essential oils are widely used in perfumes and insect repellent products. However, due to the high volatility of the constituents in essential oils, their efficacy as a repellent product is less effective than that of synthetic compounds. Using a nanoemulsion as a carrier is one way to overcome this disadvantage of essential oils. Nutmeg oil-loaded nanoemulsion (NT) was prepared using a high speed homogenizer and sonicator with varying amounts of surfactant, glycerol, and distilled water. Using a phase diagram, different formulations were tested for their droplet size and insect repellent activity. The nanoemulsion containing 6.25% surfactant and 91.25% glycerol (NT 6) had the highest percentage of protection (87.81%) in terms of repellent activity among the formulations tested for the 8 h duration of the experiment. The droplet size of NT 6 was 217.4 nm, and its polydispersity index (PDI) was 0.248. The zeta potential value was-44.2 mV, and the viscosity was 2.49 Pa.s at pH 5.6. The in vitro release profile was 71.5%. When the cytotoxicity of NT 6 at 400 µg/mL was tested using the MTS assay, cell viability was 97.38%. Physical appearance and stability of the nanoemulsion improved with the addition of glycerol as a co-solvent. In summary, a nutmeg oil-loaded nanoemulsion was successfully formulated and its controlled release of the essential oil showed mosquito repellent activity, thus eliminating the disadvantages of essential oils.

Ligusticum sinense Nanoemulsion Gel as Potential Repellent against Aedes aegypti, Anopheles minimus, and Culex quinquefasciatus (Diptera: Culicidae)

“…Therefore, formulated preparation is required to fix and control the release of plant compounds, especially active ingredients, resulting in improved protection against mosquitoes and other insects. Up until now, several researchers have reported the use of the sustained-release technology, nanoemulsions, as a suitable carrier of active essential oils against mosquito vectors [ 22 , 23 , 32 , 33 ].…”

“…However, these repellents may need frequently repeated application [ 20 ], as they provide short-lived efficacy when compared with synthetic chemicals. Therefore, the development of controlled release formulations such as cream, gel, lotion, polymer mixtures, or microcapsules are important in prolonging repellency of plant-derived products [ 21 , 22 , 23 ].…”

Development of a novel nanoemulgel formulation containing cumin essential oil as skin permeation enhancer

“…The PDI is a major predictor of homogeneity and generally is utilized to determine nanoemulsion stability [31,32]. Since the small droplet leads to a greater driving force, Ostwald ripening is one of the primary instability mechanisms in nanoemulsions [33].…”

“…In the emulsion system, the morphology of droplets is an important feature [32]. Morphology of CE nanoemulsion was compiled with mixed surfactant with HLB of 9.65 at a surfactant-to-oil ratio of 1.5.…”

Wheat Germ Agglutinin-Conjugated Disulfide Cross-Linked Alginate Nanoparticles as a Docetaxel Carrier for Colon Cancer Therapy

“…This is because PDI measures the size distributions of the nanoparticles, in which the smaller the PDI values, the narrower the size distributions of the nanoparticles. 64 Meanwhile, zeta potential measures the particle charge; as such the greater the zeta potential absolute value, the better the nanoparticle stability. 65 Therefore, TP2 nanoparticles with high zeta potentials of −45.6 mV exhibited high stability.…”