title: Microneedles: a valuable physical enhancer to increase transdermal drug delivery.
abstract: Transdermal drug delivery offers an attractive alternative to the conventional drug delivery methods of oral administration and injection. However, the stratum corneum acts as a barrier that limits the penetration of substances through the skin. Recently, the use of micron-scale needles in increasing skin permeability has been proposed and shown to dramatically increase transdermal delivery. Microneedles have been fabricated with a range of sizes, shapes, and materials. Most in vitro drug delivery studies have shown these needles to increase skin permeability to a broad range of drugs that differ in molecular size and weight. In vivo studies have demonstrated satisfactory release of oligonucleotides and insulin and the induction of immune responses from protein and DNA vaccines. Microneedles inserted into the skin of human subjects were reported to be painless. For all these reasons, microneedles are a promising technology to deliver drugs into the skin. This review presents the main findings concerning the use of microneedles in transdermal drug delivery. It also covers types of microneedles, their advantages and disadvantages, enhancement mechanisms, and trends in transdermal drug delivery.
authors.affiliation: Departamento de Ingeniería y Tecnología, Sección de Tecnología Farmacéutica, Facultad de Estudios Superiores Cuautitlán-Universidad Nacional Autónoma de México, Av. 1° de Mayo s/n. Col. Santa María las Torres, Cuautitlán Izcalli, Estado de México, C.P. 54740 México. josejuanescobarchavez@gmail.com
authors.forename: José Juan
authors.initials: JJ
authors.lastname: Escobar-Chávez
authors.forename: Dalia
authors.initials: D
authors.lastname: Bonilla-Martínez
authors.forename: Martha Angélica
authors.initials: MA
authors.lastname: Villegas-González
authors.forename: Eva
authors.initials: E
authors.lastname: Molina-Trinidad
authors.forename: Norma
authors.initials: N
authors.lastname: Casas-Alancaster
authors.forename: Alma Luisa
authors.initials: AL
authors.lastname: Revilla-Vázquez
mesh_terms: D000279:Administration, Cutaneous; D000818:Animals; D016503:Drug Delivery Systems; D004867:Equipment Design; D015316:Genetic Therapy / Q000379:methods; D006801:Humans; D055616:Microtechnology; D009339:Needles / Q000009:adverse effects; D010539:Permeability; D004364:Pharmaceutical Preparations / Q000008:administration & dosage*; D010599:Pharmacokinetics; D012867:Skin / Q000033:anatomy & histology / Q000187:drug effects / Q000378:metabolism*; D012879:Skin Physiological Phenomena; D014611:Vaccination / Q000379:methods
chemical_list: D004364:Pharmaceutical Preparations