Patent ID: 8029810

Claim:
A method of delivering an active substance through the stratum corneum, the method comprising applying to skin a delivery composition comprising: an aqueous carrier, wherein water comprises 65% or more of the delivery composition by weight; a lipid component suspended in the aqueous carrier comprising lipids consisting essentially of (a) fatty acid, which comprises 0.5-10% by weight of the delivery composition, which fatty acid is fatty acid of 10 to 24 carbons, (b) cholesterol, which comprises 0.5-7% by weight of the delivery composition, and (c) phospholipid and/or ceramide which component is 0.5-20% by weight of the delivery composition, wherein the phospholipid and/or ceramide component comprises 5% or more by weight phospholipid, and wherein the weight ratio of phospholipid/ceramide to cholesterol is 2:1 to 5.9:1, and (d) optionally, skin lipid precursors, wherein a combination of said lipids comprises 2 to 20% by weight of the delivery composition; said lipid component comprises: (i) a lipid particle component comprising particles formed from said lipids, said particles being surrounded by a lipid monolayer, the particles ranging from approximately 1 μm to approximately 150 μm in diameter, and (ii) a vesicle component comprising vesicles of formed from said lipids enclosed by a lipid bilayer, the vessicles ranging from approximately 0.02 μm to approximately 0.5 μm in diameter; and a bioactive agent suitable for delivery to or through skin.