Formulation of ultrasound-assited nanoemulsions containing eugenol

Abstract

Currently, the demand for aesthetic treatments has been increasing considerably. It often causes pain, so it is used topical anesthetic prior to the treatment. The eugenol, the main compound of the ethanol extract of Indian clove (syzygium aromaticum), is responsible for many of the pharmacologic effects attributed to this plant, including the anesthetic activity. The objective of this work was the production, characterization and assay of a nanoemulsion containing eugenol. In the production of the nanoemulsion, the evaluated parameters were: mechanical agitation at speeds of 10,000, 20,000 and 26,000 rpm, 7.5 and 15.0 minutes stirring time and the active concentration of 0.50; 0.75 and 1.00%. The formulations were characterized through the average droplet diameter, polydispersity index, zeta potential and pH, as well as the determination of the active was performed via liquid chromatography high performance (HPLC). Stability studies were performed on a 75-day period in three temperature conditions. Best results were obtained when we used mechanical stirring with 20,000 rpm for 7.5 minutes stirring time and the concentration of 1.00% active, producing nanoemulsions having an average diameter droplet 101.17 ± 6.80 nm index a polydispersity 0.135 ± 0.027, zeta potential of -7.19 ± 0.713 and pH 4.84 ± 0.04. This formulation was stable for up to 30 days, keeping the results as stored at 5 and 25ºc. As for the determination of recoveries, 72 to 106% of the assets were obtained. Thus, it is concluded that the methodology used is feasible for the production of nanoemulsions containing eugenol.