ABSTRACT
Substances found in cosmeceutical oil-in-water emulsions include oily substances such as petrolatum, mineral oil, vegetable oils, and dimethicone. The water evaporates leaving the oil behind to place a water-impermeable barrier over the skin
INTRODUCTION The ability of cosmeceuticals to induce the desired change in the skin is primarily dependent on the delivery system. The delivery system is the carrier that takes an active ingredient from a formulation and places it in the proper location to achieve an effect. Delivery systems are customized to keep the active ingredient in a certain form for a specified length of time. For example, the delivery system for a sunscreen should not be designed for stratum corneum penetration. Sunscreens function on the skin surface to either absorb or reflect ultraviolet radiation. They create a protective coating over the skin surface. Delivery of a sunscreen beneath the stratum corneum would be counterproductive; however, this is not the case for antioxidants. Oxidation occurs in the viable epidermis and dermis where cellular lipid membranes are present. Thus, an antioxidant that remains on the skin surface, such as vitamin E or green tea, provides little protection from oxidative damage. This need to place cosmeceutical ingredients in a specified compartment is the primary goal of delivery systems.
