In recent years, the sustainability of cosmetic products has received growing interest from the cosmetic industry and consumers due to the recommendation of the implementation of the circular economy and the European Green Deal. The sustainable development strategy takes into account the reduction of waste and energy consumption, and covers all processes of producing and using cosmetics, starting from the method of obtaining raw materials, through to the process of producing cosmetics bulk, to the selection of packaging. Particularly, the selection of raw materials has a large impact on sustainability of cosmetic emulsion. One way of resource recovery is the use of agro-food by-products and discarded waste to produce cosmetic raw materials, because most of them possess value-added bioactive compounds, such as enzymes and nutrients with high functionality. Their recovery may be performed by more sustainable extraction processes, leading to natural oils, extracts, polymers, phytosterols, vitamins, minerals, and unsaturated fatty acids. A relatively new and innovative form of designing sustainable and bioavailable cosmetic raw materials is fermentation, where bioferments are obtained from plant-based and food waste raw materials. In addition, optimization of the emulsification process by applying low-energy methods is a crucial step in obtaining sustainable cosmetics. This allows not only a reduction in the carbon footprint, but also the preservation of the valuable properties of the used raw materials. The following paper discusses methods of creating sustainable cosmetic emulsions with energy-saving procedures and by using raw materials from food waste and the fermentation process.

Centella asiatica 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 Centella asiatica 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 Centella asiatica 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.