Penetration, nanoemulsions

Nanoemulsions are suitable for the efficient delivery of active ingredients through the skin. The large surface area of the emulsion system allows the rapid penetration of active agents. 

Due to their small size, nanoemulsions can penetrate the rough, skin surface and this enhances the penetration of active agents. 

The small size of the droplets allows nanoemulsion to be deposited uniformly on substrates. Wetting, spreading and penetration may be also enhanced as a result of the low surface tension of the whole system and the low interfacial tension of the O/W droplets. 

Nanoparticles in skincare products include various types of dehvery systems and can be subdivided on the basis of the encapsulating membrane structure into hposomes, nanoemulsions, nanosomes, and nanotopes. They can carry many actives to penetrate into skin quickly and into intracellular structures while conventional skincare products usually do not penetrate the skin and release the active by diffusion or by capsule destruction. Nanoparticles also bring up many other new applications. For example, skin whitening or Kghtening is a more recent apphcation in which actives carried by nanoparticles penetrate beyond the skin barrier, and more active reaches the necessary site of action in the skin, resulting in improved performance. 

Nanoemulsioms are transparent or translucent systems. Due to their small droplet size, nanoemulsions are stable against creaming, or seimentation, flocculation, and coalescence. A main advantage is that high occlusive film may be formed on application to the skin. Another useful application is the ability to enhance penetration of actives (e.g., vitamins) into skin. This is due to their much higher surface area when compared to coarser emulsions (31). 

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