Topical niacinamide enhances hydrophobicity and resilience of corneocyte envelopes on different facial locations.

The stratum corneum (SC) undergoes a variety of catabolic and anabolic reactions towards its outer surface layers in preparation for its external assault from the terrestrial environment. These events are essential for the formation of a healthy barrier. Key is the maturation of the corneocyte envelope (CE) (Fig. 1). Morphologically CE's appear fragile in the deeper layers of the SC and more rigid in the outer layers, the mechanics of which have been confirmed with several biomechanical approaches.