Production of Nanoliposomes by a Supercritical CO2 Assisted Process: Application to Cosmetics

Vesicles are intriguing candidates for the topical administration of cosmetics as they can act as skin penetration stimulators, the individual components of the vesicles can impart additional desired properties to cosmetics, and are biodegradable and minimally toxic. Among the vesicular systems proposed for this application, liposomes are widely investigated. They are constituted of an inner aqueous core and an outer lipid bilayer. This configuration allows the encapsulation of both lipophilic and hydrophilic bioactive drugs. However, the traditional processes proposed for the production of these vesicles suffer from several limits: they are batch and time-consuming techniques, require post-treatments for the purification of vesicles from organic solvent residues and/or for reducing their mean size, do not favour a high encapsulation efficiency of drugs. In this work, SuperSomes, a sustainable and continuous process assisted by supercritical CO2, was used to produce nanometric liposomes loaded with ascorbic acid for cosmetic applications. Operating at 100 bar and 40 °C, stable liposomes characterized by a spherical morphology and a mean diameter lower than 250 nm, were obtained. An ascorbic acid encapsulation efficiency of 85% was measured and the supercritical process preserved the antioxidant activity of the drug.