title: Iontophoresis of minoxidil sulphate loaded microparticles, a strategy for follicular drug targeting?
abstract: The feasibility of targeting drugs to hair follicles by a combination of microencapsulation and iontophoresis has been evaluated. Minoxidil sulphate (MXS), which is used in the treatment of alopecia, was selected as a relevant drug with respect to follicular penetration. The skin permeation and disposition of MXS encapsulated in chitosan microparticles (MXS-MP) was evaluated in vitro after passive and iontophoretic delivery. Uptake of MXS was quantified at different exposure times in the stratum corneum (SC) and hair follicles. Microencapsulation resulted in increased (6-fold) drug accumulation in the hair follicles relative to delivery from a simple MXS solution. Application of iontophoresis enhanced follicular delivery for both the solution and the microparticle formulations. It appears, therefore, that microencapsulation and iontophoresis can act synergistically to enhance topical drug targeting to hair follicles.
authors.affiliation: School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo. Av. do Café s/n, 14040-903 Ribeirão Preto, SP, Brazil; Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, BA2 7AY, Bath, UK; Laboratory of Food, Drugs and Cosmetics (LTMAC), School of Health Sciences, University of Brasília, Campus Universitário Darcy Ribeiro, s/n, 70910-900 Brasília, DF, Brazil.
authors.forename: Guilherme M
authors.initials: GM
authors.lastname: Gelfuso
authors.affiliation: School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo. Av. do Café s/n, 14040-903 Ribeirão Preto, SP, Brazil.
authors.forename: M Angélica de Oliveira
authors.initials: MA
authors.lastname: Barros
authors.affiliation: Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, BA2 7AY, Bath, UK.
authors.forename: M Begoña
authors.initials: MB
authors.lastname: Delgado-Charro
authors.affiliation: Department of Pharmacy & Pharmacology, University of Bath, Claverton Down, BA2 7AY, Bath, UK.
authors.forename: Richard H
authors.initials: RH
authors.lastname: Guy
authors.affiliation: School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo. Av. do Café s/n, 14040-903 Ribeirão Preto, SP, Brazil. Electronic address: rvianna@fcfrp.usp.br.
authors.forename: Renata F V
authors.initials: RF
authors.lastname: Lopez
mesh_terms: D000818:Animals; D016503:Drug Delivery Systems; D018859:Hair Follicle / Q000187:drug effects*; D066298:In Vitro Techniques; D007478:Iontophoresis; D008914:Minoxidil / Q000008:administration & dosage / Q000031:analogs & derivatives*; D013552:Swine
chemical_list: C039516:minoxidil sulfate ester; D008914:Minoxidil
keywords: Chitosan; Hair follicle; Iontophoresis; Microparticle; Minoxidil sulphate; Topical drug delivery