Controlled Release of Madecassoside and Asiaticoside of Centella asiatica L. Origin from Sustainable Cold-Processed Topical Formulations

<i>Centella asiatica</i> L. extract is a promising natural agent for the treatment of atopic dermatitis. It significantly reduces inflammation due to its immunomodulatory properties, mainly attributed to the presence of pentacyclic triterpenes, namely madecassoside and asiaticoside. Their incorporation into sustainable cold-processed topical formulations, such as emollient-rich emulsions and cosmetic gel containing natural hydrophilic polymers, should inhibit inflammation in atopic skin. Therefore, the objective of this study is to investigate the controlled release of madecassoside and asiaticoside isolated from <i>Centella asiatica</i> L., loaded into topical formulations, namely emollient-rich O/W and W/O emulsions and cosmetic gel, which could support the treatment of atopic dermatitis. The carriers of active substances have been prepared with sustainable emulsifiers, active substances, and emollients obtained by green technologies from food industry wastes. Low-energy methods during the carrier emulsification process were applied to reduce carbon footprints and preserve the valuable properties of the raw materials used. The influence of the <i>Centella asiatica</i> L. extract on the physicochemical properties of the formulations was studied, showing a satisfactory degree of stability of the formulations obtained. Moreover, factors that may influence the mechanism and kinetics of the release of madecassoside and asiaticoside, such as the concentration of the active substance, the pH of the dissolution medium, and the type of the carrier, have been tested and widely discussed.