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™ 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™ 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.