Hair fiber and scalp surface

The hair fiber and scalp surface represent a complex anatomical and physiological environment that serves as the primary site for topical dermatological and trichological interventions. The scalp is characterized by a high density of terminal hair follicles and large sebaceous glands, creating a unique microenvironment and a significant barrier for drug penetration [1][3]. The hair fiber itself is a non-living, highly keratinized structure consisting of the cuticle, cortex, and sometimes a medulla, which can be targeted for structural repair or aesthetic modification [1][4]. While not a single molecular target, this site is the focus of treatments for conditions such as androgenetic alopecia, seborrheic dermatitis, and psoriasis [2][5]. Drugs interacting with this surface often aim to modulate follicular activity, reduce fungal populations like Malassezia, or restore the epidermal barrier [2][3]. Understanding the physicochemical properties of the hair and scalp is crucial for the formulation of shampoos, foams, and lotions to ensure efficacy and minimize irritation [2][4]. Citations: [1] Robbins CR. Chemical and Physical Behavior of Human Hair. Springer Science & Business Media; 2012. [2] Trüeb RM. Shampoos: Ingredients, efficacy and adverse effects. J Dtsch Dermatol Ges. 2007. [3] Grice EA, Segre JA. The skin microbiome. Nat Rev Microbiol. 2011. [4] Sinclair R. Healthy Hair: What Is It? J Investig Dermatol Symp Proc. 2007. [5] Bolduc C, Shapiro J. Management of androgenetic alopecia. Am J Clin Dermatol. 2000.

Other names

CapillitiumScalp epidermisHair shaftPilocutaneous surface

Topical delivery of active ingredients to the hair follicle or stratum corneum; physical coating and cuticle repair; antifungal activity against Malassezia species; anti-inflammatory modulation of the scalp dermis; keratolytic breakdown of scales.