The obtention of an oil/water nanoemulsion containing the Calceolaria chelidonioides flowers ethanol extract and its skin hydration power

Abstract

Nanoemulsions are biphasic systems with droplet size in the nanometric scale (20–200nm). Oil/water nanoemulsions are promising colloidal drug carrier systems for diverse therapeutic applications as topical, intravenous, oral and ocular [1]. They are non-equilibrium systems, a high energy input generally from mechanical devices or from the chemical potential of the components, is required for their formation [2]. In this work we prepared an oil/water nanoemulsion with the ethanolic extract obtained from flowers of Calceolaria chelidonioides 5% with droplet size of 45,46±3,64nm and high stability using a classical macroemulsion protocol by mixing two formulation concepts, the H.L.B. and the phase diagram, to choose the best non-ionic surfactant match. Calceolaria chelidonioides is an original Brazilian plant belonging to the Scrophulariaceae family. This plant has been studied in our group and we were able to identify its antimicrobial and antioxidant properties [3]. We evaluate this nanoemulsion skin hydration power in vivo with female volunteers between (20–40 years old). The measurement of the skin humidity was carried out by a Corneometer® CM820 using the capacitance method, before and 10, 20, 30, 45 minutes after the administration. Two moisturizing comercial products well known by its properties, Nivea Soft® from Nivea® and Ictyane® from Ducray® were used as control, and the formulated nanoemulsion without the plant active was evaluated. The C. chelidonioides' nanoemulsion showed some interesting skin hydration actitvity higher than Nivea Soft® cream, especially after 45 minutes, showing an increase of 25% in skin hydration. However, the most important hydration power was obtained with the nanoemulsion base which showed 30% of increase after 45 minutes.