Essential oils have known a renewed interest, particularly for their antimicrobial properties. In the field of skin delivery of
essential oils, fluid oil-in-water (O/W)
emulsions have been studied for several years in order to improve their stability. When dealing with
infections of the upper skin layers, these vehicles, in spite of their low viscosity, must have a good skin persistence and also concentrate the
essential oil components in the target skin layers. Given the well-known ability of alkylsiloxysilicate resins to induce a very substantive and non-occlusive film after cutaneous application in an appropriate preparation, it has been undertaken to use them to prepare a highly persistent O/W fluid
emulsion of
essential oil. Hence, after the successful development of a fluid
silicone-in-water (Si/W)
emulsion integrating a 100% trimethylsiloxysilicate resin, the
essential oil was incorporated in this
emulsion. The physical and chemical stabilities of the prepared
emulsion were then studied in the final packaging under different storage conditions. In addition, the skin penetration profile of
essential oil from this vehicle was investigated, ex vivo, on pig ear skin, using Franz diffusion cells and analytical techniques such as confocal Raman microscopy. As the developed vehicle was found to meet our delivery expectations, its skin tolerance has been proven by an in vivo chromametric evaluation of its
irritant potential. The skin persistence of this
emulsion containing an antimicrobial
essential oil was then studied. Considering its properties, the developed
emulsion is expected to represent a real asset in the treatment of skin
infections, particularly
infections of upper layers of human skin such as
dermatophytosis.