cosmetics Review Topical Minoxidil-Loaded Nanotechnology Strategies for Alopecia 1,2, , 1, 1 1 Ana Cláudia Santos * y , Miguel Pereira-Silva y , Catarina Guerra , Diana Costa , Diana Peixoto 1, Irina Pereira 1,2, Inês Pita 1, António J. Ribeiro 1,3 and Francisco Veiga 1,2 1 Department of Pharmaceutical Technology, Faculty of Pharmacy of the University of Coimbra, University of Coimbra, Azinhaga Sta. Comba, 3000-548 Coimbra, Portugal;
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[email protected] (F.V.) 2 REQUIMTE/LAQV, Group of Pharmaceutical Technology, Faculty of Pharmacy of the University of Coimbra, University of Coimbra, Azinhaga Sta. Comba, 3000-548 Coimbra, Portugal 3 i3S, Group Genetics of Cognitive Dysfunction, Institute for Molecular and Cell Biology, Rua do Campo Alegre, 823, 4150-180, Porto, Portugal * Correspondence: acsantos@ff.uc.pt Ana Cláudia Santos and Miguel Pereira-Silva contributed equally for this work. y Received: 22 February 2020; Accepted: 26 March 2020; Published: 27 March 2020 Abstract: Androgenetic alopecia (AGA) is a multifactorial and age-related condition characterized by substantial hair loss affecting both men and women. Conventional treatments include the use of topical minoxidil (MNX) formulations to stimulate hair growth and restore hair condition. However, those treatments are associated with limited performance and a lack of tolerability and compliance due to the emergence of adverse effects. Considering that the development of nanotechnology-based formulations as hair loss therapeutic strategies has been clearly growing, topical MNX delivery by means of these innovative formulations is known to enhance MNX skin permeation and depot formation into hair follicles, allowing for MNX-controlled release, increased MNX skin bioavailability and enhanced therapeutic efficacy with minimal adverse effects.