title: Microneedles for intradermal and transdermal drug delivery.
abstract: The formidable barrier properties of the uppermost layer of the skin, the stratum corneum, impose significant limitations for successful systemic delivery of broad range of therapeutic molecules particularly macromolecules and genetic material. Microneedle (MN) has been proposed as a strategy to breach the stratum corneum barrier function in order to facilitate effective transport of molecules across the skin. This strategy involves use of micron sized needles fabricated of different materials and geometries to create transient aqueous conduits across the skin. MN, alone or with other enhancing strategies, has been demonstrated to dramatically enhance the skin permeability of numerous therapeutic molecules including biopharmaceuticals either in vitro, ex vivo or in vivo experiments. This suggested the promising use of MN technology for various possible clinical applications such as insulin delivery, transcutaneous immunisations and cutaneous gene delivery. MN has been proved as minimally invasive and painless in human subjects. This review article focuses on recent and future developments for MN technology including the latest type of MN design, challenges and strategies in MNs development as well as potential safety aspects based on comprehensive literature review pertaining to MN studies to date.
authors.affiliation: School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, Northern Ireland, UK; Faculty of Pharmacy, The National University of Malaysia (UKM), Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia.
authors.forename: Tuan-Mazlelaa
authors.initials: TM
authors.lastname: Tuan-Mahmood
authors.forename: Maelíosa T C
authors.initials: MT
authors.lastname: McCrudden
authors.forename: Barbara M
authors.initials: BM
authors.lastname: Torrisi
authors.forename: Emma
authors.initials: E
authors.lastname: McAlister
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Garland
authors.forename: Thakur Raghu Raj
authors.initials: TR
authors.lastname: Singh
authors.forename: Ryan F
authors.initials: RF
authors.lastname: Donnelly
mesh_terms: D000279:Administration, Cutaneous; D000818:Animals; D003952:Diagnostic Imaging; D016503:Drug Delivery Systems; D006801:Humans; D020100:Hydrogels; D008845:Microinjections / Q000009:adverse effects; D009339:Needles / Q000009:adverse effects; D010146:Pain / Q000209:etiology; D010465:Perception; D012867:Skin / Q000382:microbiology
chemical_list: D020100:Hydrogels
keywords: Drug monitoring; Hydrogel-forming; Microneedle; Safety; Transdermal drug delivery; Vaccination