Lipoprotein creams: utilization of multifunctional ingredients for the preparation of cosmetic emulsions with excellent skin compatibility.

ABSTRACT

Lipoproteins are plant-derived surface-active biopolymers, which act as emulsifying as well as viscosity-enhancing agents in oil-in-water emulsions. Depending on the degree of hydrolization, lipoproteins are dispersible or even soluble in water. In the presence of low to medium polar oils, lipoproteins are adsorbed and align at the oil-water interface, whereas in mixtures with high polar oils the lipoproteins are repelled from the oil-water interface. The water-dispersible lipoproteins show higher interfacial activity than the hydrolysates. Lipoproteins bear a negative electric charge in aqueous dispersions at pH 6.5, which is probably the reason for the stabilization of oil droplets against coalescence. Lipoprotein creams were characterized in terms of particle size, rheology, and emulsion stability against sedimentation, which was evaluated by a near-infrared sedimentometer. After topical application, emulsion stability breaks down and an emulsion film is formed on the skin surface. Lipoprotein creams cause a distinct increase in skin pliability and skin moisture and show excellent skin compatibility. In a home use test the panelists appreciated the cosmetic and caring properties of the lipoprotein cream.