A unique long term stable carrier system for poorly soluble drugs was obtained by simply autoclaving nanostructured lipid carriers (NLC). NLC composed of Precirol ATO, oleic acid, glycerol 85%, Eumulgin SML 20 and water as well as NLC loaded with the poorly soluble drug Itraconazole formed a special organized matrix containing lamellar bilayers similar to biological membranes after the sterilization process. The tendency to expel the poorly soluble drug from the matrix was thereby avoided.