96Skin, the largest organ in the body, functions as a protective barrier as well as maintains fluid homeostasis, provides thermoregulation of the human body, mediates sensory detection and is the major site for transdermal delivery of actives. Human skin consists of two major layers: (a) the epidermal layer, that is mainly composed of proliferating and differentiated keratinocytes and (b) an underlying dermal layer that is rich in fibroblasts, connective tissue and blood vessels.