First Aid Beauty

The Importance of Barrier Protection

The skin is responsible for a number of vital functions, ranging from first-line defense against bacterial and viral pathogens to maintaining our body’s temperature and electrolyte balance. It is the largest organ of the human body and contains within it millions of immune cells on constant surveillance. Remarkably, the skin’s edge must also be largely impervious to water and UV light, while letting in just the right amount to complete important biochemical functions. Moreover, the dermis serves as the last frontier against blood and water loss from the inside out.

It is for this seemingly paradoxical structure and function, that the dermis holds such a unique challenge for pharmacologists. Chemists compounding topical medications for use in dermatology are challenged to first circumvent the skin’s natural barrier to the outside world and, once there, prevent their active from either being destroyed by the skin’s immune system or else just seeping back out through the skin’s many pores. That’s very difficult! Delivery systems for any topically applied agent are just as important as the actives themselves. The most amazing anti-aging, active ingredient will have zero effect if chemists cannot deliver its full impact deep into the dermis where it will have the opportunity to effect change.

Delivery systems have gone though a tremendous evolution over the last 50 years. The original standard, and still widely used, is a petrolatum base (think Vaselinetm). Petrolatum enables embedded active ingredients to stay put once placed in the skin because of its occlusive properties. This is great for keeping water from escaping, but not so helpful when trying to get actives deep within the dermis. On the other extreme is a chemical called dimethyl sulfoxide (DMSO). When linked with certain actives, this penetration enhancer is so good, it often skips the dermis and heads straight to the underlying blood stream. A potentially fatal proposition depending upon what DMSO is linked to.

An ideal “happy medium” are ceramides. These naturally occurring lipids serveas intercalators, sliding between skin cells to deliver great hydration that stays situated between collagen fibrils of the dermis. An appropriate ceramide : triglyceride : cholesterol ratio not only ensures that active ingredients are delivered deep within the dermis, but also protects valuable hydration and electrolytes from being unnecessarily excreted through the skin’s surface.