Evaluation of Stability and In Vitro Security of Nanoemulsions Containing Eucalyptus globulus Oil

Abstract

Essential oil of Eucalyptus globulus presents several pharmacological properties. However, their therapeutic efficacy may be affected by limitations due to several conditions, rendering it difficult to obtain stable and effective pharmaceutical formulations. The use of nanotechnology is an alternative to improve their characteristics aiming to ensure their stability and effectiveness. Furthermore, studies about the possible toxic effects of nanostructures are necessary to evaluate safety when the formulation comes into contact with human cells. Hence, in this paper, we evaluate for the first time the stability and in vitro cytogenotoxicity of nanoemulsions containing Eucalyptus globulus in peripheral blood mononuclear cells. As a result, the stability study found that the best condition for storage up to 90 days was refrigeration (4°C); it was the condition that best preserved the nanometric features. The content of the major compounds of oil was maintained after nanoencapsulation and preserved over time. In tests to evaluate the safety of this formulation, we can conclude that, at a low concentration (approximately 0.1%), Eucalyptus globulus nanoemulsion did not cause toxicity in peripheral blood mononuclear cells and also showed a protective effect in cells against possible damage when compared to oil in free form.

Efectos del aceite esencial de Eucalyptus globulus cargado en nanoemulsiones y en nanocápsulas en la reproducción de la garrapata bovina (Rhipicephalus microplus)

“…and nanocapsules (NC) containing Eucalyptus globulus essential oil regarding size (NE 69 ± 0.71; NC 162.1 ± 1.25), polydispersity (NE 0.20 ± 0.01; NC 0.165 ± 0.01), potential zeta (NE -16.5 ± 0.65; NC -14.3 ± 0.60) and pH (NE 4.68 ± 0.04; NC 4.71 ± 0.06), as previous describe by Godoi et al (2017).…”

“…The essential oil was commercially obtained from Ferquima Ltda (Vargem Grande Paulista, São Paulo, SP, Brazil), and was subjected to the characterization (Godoi et al, 2017). The gas chromatography (GC) analyses was performed with a gas chromatograph Varian one Star 3400CX (CA, USA) equipped with a flame ionization detector (GC-FID).…”

“…The constituents of essential oil of E. globulus were described by Godoi et al (2017). Twelve components, representing 100% of total composition, were identified.…”

“…The nanoemulsion and nanoparticles were prepared, having a final concentration of 5% of essential oil of E. globulus. The nanoemulsion was prepared according the method of emulsification under high agitation using Ultra Turrax ® , as described by Godoi et al (2017). The oil phase was composed by E. globulus essential oil and sorbitan monooleate (Span 80), while the aqueous phase was composed by polysorbate 80 (Twenn 80) and 25 mL of ultra-pure water.…”

Oil-In-Water Microemulsions for Thymol Solubilization

“…Therefore, it is necessary to design procedures for enhancing their availability without compromising their properties. Previous studies have reported that nanoemulsions and microemulsions are promising options for the preparation of eco-sustainable platforms that enable EOC solubilization, enhancing, in most of cases, their biological activity [20,21]. Furthermore, other alternatives, such as gel-like and solid lipid particles, liposomes or cyclodextrins, have also been explored for encapsulation of EOCs.…”