Liquid crystals as a potential ointment vehicle

A lecithin-water lyotropic liquid crystal was used as an ointment vehicle for a hydrocortisone formulation. The hydrocortisone was soluble in the liquid crystalline phase up to 5% by weight. The diffusion coefficient determined for the hydrocortisone in the liquid crystalline phase was 5.5 X 10(-9) cm X s-1, which is four magnitudes higher than the corresponding value for skin.