The essential oil of Lippia origanoides is of great pharmacological interest because of a wide variety of attributes, in particular its antifungal action. Due to its low solubility in aqueous media, high volatility, and a high propensity for physicochemical degradation, the search for nanostructured systems to promote the stability of this phytocomplex is necessary. Nanoemulsion is an alternative method to stabilize and preserve this type of active ingredient, especially when generated by a low energy method and using Syagrus coronata (licuri) oil as an active carrier and stabilizer of this nanostructure. The objective of the present investigation was to formulate a stable nanoemulsion with Lippia origanoides essential oil carried through licuri oil with antifungal action by the low energy method. For this, we began with the extraction of the essential oil and the phytochemical characterization obtaining the chemotype B of this Lippia (carvacrol: 49.12%). Then, using the pseudoternary phase diagram, the optimal ratio of the oil phase 6:4 (essential oil: Syagrus coronata oil) was established, adding 15% of surfactant (polysorbate 80) and 75% of the aqueous phase. Then, with the formulated nanoemulsion, the physical-chemical characterization and evaluation of preliminary and accelerated stability were carried out. In addition, cytotoxicity, Franz cell permeation and antifungal activity against dermatophytes were evaluated. A stable nanoemulsion was obtained by the low energy method with the characteristic appearance of a nanoemulsion and a characteristic odor of essential oil. The average size of the nanoparticles was around 167.5 nm, narrow PDI (<0.2 nm), zeta potential below -10.0 mV, acidic pH (5.1), average conductivity 134.4 μSm/cm, refractive index characteristic of a translucent system and low viscosity (<6.0 mPa.S). Regarding cytotoxicity, it proved to be safe at dosages below 90 μg/mL, efficient in terms of permeation (76.7% in 24h) and effective in terms of antifungal activity as it had a minimum inhibitory concentration between 234.4/156.3 μg /mL and 11.2/7.5 μg/mL against the tested dermatophytes. In view of the results, a nanoemulsion containing the essential oil of L. origanoides carried by the oil of Syagrus coronata was shown to be a potential product for the topical treatment of fungal infections like dermatophytosis.
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