According to general considerations about corneotherapy (Albert M. Kligman) the chemical composition and the physical structure of base creams play a major role in supporting the homoeostasis of the skin. From the physiological point of view membrane forming ingredients should be preferred due to the compounds and bilayer structure of intercellular lipids of the horny layer. Typical membrane forming agents are ceramides, cholesterol, fatty acids and phospholipids. Among phospholipids phosphatidylcholine (PC) meanwhile is the most important starting material, because of availability and different behaviour with regard to chemically bonded fatty acids. Native PC is a source of linoleic acid while fluidizing skin barrier and supporting ceramide I formation whereas hydrogenated PC (PC-H) shows strong barrier protection activities. In this respect definite ratios of PC and PC-H together with materials influencing skin hydration and skin smoothness are of special interest for preventing and treating atopic skin. Because of the lamellar structure of such systems they behave like the skin; that means they are able to take up hydrophilic and lipophilic active agents at room temperature, an important prerequisite for their use as base creams. As a result the base creams enable a construction kit in combination with simple skin analysis procedures like corneometry, sebumetry and tewametry. Furthermore there is no break between medical treatment and cosmetic prevention. Experiences from practice show a high efficacy and tolerance with regard to atopic dermatitis.
Dr. Hans Lautenschläger