Glycerol-based liposomal systems

Lecithins, especially phosphatidylcholines, spontaneously form lipid bilayers of spherical (liposomes) or lamellar structures in an aqueous surrounding. Amongst other things, liposomes can be used to encapsulate cosmetic actives to support their penetration into the epidermis. Due to their high water content, liposomal systems need to be preserved by using either conventional preservatives or a self preserving solvent system. As glycerol is the second most used raw material in the cosmetic industry, we have chosen to study a glycerol/water mixture for a new self-preserving liposome-like system. We examined several variations of glycerol-based liposomal preparations regarding their use in formulations, their particle size as well as their physical and microbiological stability. The results show that our novel glycerol-based liposomal preparations have similar properties and functionality as conventional water-based liposomal systems but do not require the addition of any preservative. As a conclusion, we find that glycerol can overtake the role of water for the formation of liposomal products being the foundation for a new generation of liposomes.