Possibilities of liposomes as dynamic dosage form in dermatology

Local application of substances in different vehicles for the care of the skin and the treatment of skin diseases have been used since antiquity. With the present state of technology a modern dosage form allowing chemical engineering can be devised. Liposomes which consist of lipid bilayers engulfing an aqueous solution fulfill the sophisticated requirements. With a lipid and an aqueous compartment these liposomes can contain lipophilic and hydrophilic medicaments. The lipid composition and the incorporation of charged carrier protein molecules can be varied, affecting the rate of drug release to the skin. In this way active substances are either retained on the skin (pertinent to sunscreening agents) or liberated from the liposome depot to the skin layers (corticosteroids). The highly organized membrane structures containing lysine or hydrolysine can be fixed to the skin enzymatically avoiding temporal removal from the skin and supporting depot function and protective film function. Studying the surface lipid and epidermal lipid composition, lipid membranes can be composed which do not cause hypersensitivity reactions and form a substitute in case of deficient barrier function of the skin.