Niosomal Nanoformulations for Targeted Follicular Drug Delivery in Alopecia: An Integrative Review of Pathophysiology, Therapies, and Nanotechnology-Based Approaches

Alopecia encompasses a heterogeneous group of scarring and non-scarring hair loss ‎disorders that, although not life-threatening, exert profound psychosocial, economic, and quality-‎of-life burdens. This review synthesizes current knowledge on the epidemiology, clinical features, ‎and pathophysiology of major alopecia entities, including cicatricial forms such as lichen ‎planopilaris, frontal fibrosing alopecia, and central centrifugal cicatricial alopecia, as well as non-‎scarring forms such as androgenetic alopecia, telogen effluvium, traction alopecia, and alopecia ‎areata. Conventional therapeutic approaches—topical and systemic corticosteroids, contact ‎immunotherapy, immunosuppressants, JAK inhibitors, phototherapy, platelet-rich plasma, and ‎minoxidil—are critically appraised with respect to efficacy, safety, and limitations in targeting the ‎hair follicle. Building on these foundations, the article explores advances in dermal and ‎Transfollicular drug delivery using nanocarriers, with particular emphasis on lipidic and non-ionic ‎surfactant vesicles, especially niosomes. Their composition, methods of preparation, mechanisms ‎of follicular targeting, and advantages over classical topical vehicles are discussed. Finally, ‎cetirizine dihydrochloride is highlighted as a repurposed antihistamine with prostaglandin-‎modulating, anti-inflammatory, and potential hair growth–promoting properties, for which ‎niosomal delivery may enhance local bioavailability while minimizing systemic exposure. ‎Integrating dermatological pathobiology with pharmaceutical nanotechnology, the review outlines ‎a rationale for niosomal cetirizine as a promising strategy in alopecia management. This paradigm ‎warrants rigorous multi-center evaluation.‎