Unit for Drug Research and Development, North-West University, Potchefstroom, South Africa.
Skin Pharmacol Physiol. 2011;24(6):330-6. doi: 10.1159/000330385. Epub 2011 Aug 11.
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.
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.
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.
两种类型的皮肤老化（内在的和外在的）具有重要的分子特征，而在大分子水平上有明显的区别：两者都导致活性氧的产生增加，基质金属蛋白酶表达增强，原胶原蛋白合成减少。L-肉碱酒石酸盐已被报道具有抗衰老作用。
本研究通过Franz 扩散池，使用液相色谱/质谱分析，考察了 L-肉碱在有和没有 Pheroid™ 作为递送系统的情况下，递送到女性腹部皮肤角质层和表皮-真皮靶部位的输送和转运情况。还研究了内源性 L-肉碱在人体皮肤中的存在情况。
Pheroid™ 递送系统增强了 L-肉碱通过皮肤的扩散，尽管磷酸盐缓冲液（PBS）显示皮肤层中活性物质的浓度更高。这可能是因为 Pheroid 比 PBS 更亲脂，从而改善了 L-肉碱通过皮肤层的扩散，因此导致递送到靶部位（即表皮-真皮）的 L-肉碱量减少。
