Title : Nanocarriers in cosmetics & skin care-a cosmetic chemist point of view
Many papers and reviews have been published during the last 10 years about transdermal bioactive nanocarriers. Nevertheless, most of those publications have been directed towards medical and therapeutic applications, where it is necessary to introduce drugs into the systemic circulation of mammals to reach specific sites, as cancerous cells or for imaging agents. Instead, few reports have been written about their usage in cosmetics. The author thinks that the reason has origin in the very definition of what a cosmetic is, the limitations that it imposes and the safety concerns. Thus, instead of bolstering penetration, nano-cosmetics try keep active molecules not farther the Stratum Basale or, at most, the dermis. A controlled release is suited both to increase bioavailability and, in some cases, to reduce irritation. Due to those reasons, the usual size of nano-compounds found in cosmetics should be tuned in the 50-300 nm range.
A short review of different types of the compounds used is presented, as well as their usual pathways for skin penetration. Some practical examples are given, both from research as from the literature.
The possibility to design nanocarriers able to reach specific targets and deliver different kind of substances in a controlled manner is changing the state of the art, opening new roads to the formulators and to the cosmetic industry.