ABSTRACT
This chapter discusses different aspects of the hairs and hair follicles. Hair morphology is different in various ethnic groups. As the hair follicle represents a disruption of the skin barrier, the hair follicles play an important role as a penetration pathway for percutaneous absorption and as a long-term reservoir for topically applied particulate substances. The permanent part of the hair follicle combines the infundibulum, the isthmus and the bulge region. The transient part of the hair follicle is the region between the bulge and the hair bulb. A very promising strategy is to use nanocarriers exclusively as transporters for drugs in the hair follicles. Nanocarriers represent a heterogeneous group of particulate substances which are expected to improve drug delivery significantly in many fields of medicine, pharmacology and cosmetics. In order to use the positive properties of nanocarriers for improved drug delivery, new strategies for the effective use of nanocarriers have to be developed.
