Pilosebaceous Targeting - An Emerging Concept in Topical and Cosmetic Science

Pilosebaceous targeting involve targeting to pilosebaceous unit which is comprises of hair follicle and associated glands. Skin is of great interest for pharmaceutical and cosmetic industry. Topically applied substances penetrate into skin via transcellular, intercellular, and follicular paths. Follicular path has been largely ignored because hair follicles constitute only 0.1% of total skin. Nonetheless, hair follicle has great potential for skin treatment, owing to its deep extension into the dermis and thus provides much deeper penetration and absorption of compounds beneath the skin than seen with transdermal route. Pilosebaceous targeting follows this follicular path and opens a new stratergy for topical drug delivery. Pilosebaceous targeting offers opportunities for localized delivery in hair therapy and treatment of hair follicle associated diseases like alopecia, acne and skin cancer as well as in gene therapy which is given during cancer chemotherapy to overcome loss of hair or hair colour. Hair follicle is also an entry point for topically applied substances and significantly contributes to the transport of drugs into the skin. Therefore, pilosebaceous targeting helps systemic delivery of drugs via hair follicle. Targeting to pilosebaceous unit can be done by using nanocarriers like liposomes, niosomes, microspheres and nanoparticles. The follicular penetration of topical compounds can be investigated in vivo by laser scan microscopy, fluorescence microscopy, atomic force microscopy (AFM), autoradiography, etc.