Topical and Transdermal Delivery of L-Carnitine

Background: The two types of skin aging (intrinsic and extrinsic) share important molecular features, while having distinct differences on the macromolecular level: both lead to increased production of reactive oxygen species, enhanced matrix metalloproteinase expression and decreased procollagen synthesis. L-Carnitine L-tartrate has been reported to have anti-aging effects. Aim and Methods: The delivery as well as the transport of L-carnitine to the target sites, i.e. stratum corneum and epidermis-dermis of female abdominal skin, with and without the use of Pheroid (TM) as delivery system, were investigated during this study by use of Franz diffusion cells and analysed by liquid chromatography/mass spectrometry. The presence of endogenous L-carnitine in human skin was also investigated. Results and Conclusion: The Pheroid (TM) delivery system enhanced the diffusion of L-carnitine through the skin, although the phosphate buffer solution (PBS) showed a higher concentration of the active agent in the skin layers. This could be because Pheroid, being more lipophilic than PBS, improved the diffusion of L-carnitine through the skin layers, consequently leading to a lesser amount of L-carnitine delivered to the target site, i.e. the epidermis-dermis. Copyright (C) 2011 S. Karger AG, Basel