Penetration and Distribution in Human Skin Focusing on the Hair Follicle

The document from 2005 explores the potential of targeting drugs to specific areas of the skin, particularly the hair follicle, to treat conditions like acne, cancer, and alopecia. It suggests that increasing drug concentration at the action site while reducing systemic circulation can be achieved by selecting appropriate formulations and drug properties. The paper notes that the follicular route of penetration may be significant, especially in the initial phase of transdermal transport, and that the density of hair follicles on the scalp and face could enhance absorption. However, it concludes that while targeting the upper regions of the dermis is possible, reaching the hair bulb through topical application is difficult and requires highly potent molecules. The document also emphasizes the need for more research to understand the overall contribution of the follicular route to skin transport and the influence of formulations and chemical properties on this process.