title: In vitro characterization of the invasiveness of polymer microneedle against skin.
abstract: The micro-sized needles could pierce the skin to deliver drugs effectively in a minimally invasive and painless manner. However, there are only a few reports that identify the invasiveness and painlessness of microneedle (MN), and in vitro characterization studies were conducted to examine the invasiveness of MN in experimental animals and healthy volunteers. First, a fluorescent molecule was applied to show the skin holes according to the application time of MN and then the whitening effect in UV-exposed hairless rats was observed using reflectance spectroscopy according to the application time of MN. The extent of skin irritation by the application time of MN in healthy volunteers was determined from the value of skin redness. Regardless of MN application time, skin redness occurred and then disappeared 30 min after removal of MN; this phenomenon was insignificant with the application time of MN. Thus, if the MN was applied, a skin hole appeared, skin redness was observed and then the skin redness disappeared 30 min after removal of MN. Taken together, polymer MN might be a suitable tool for safe transdermal drug delivery of small molecules.
authors.affiliation: College of Pharmacy and Institute of Drug Research and Development, Chungnam National University, Daejeon 305-764, South Korea.
authors.forename: Young-Wook
authors.initials: YW
authors.lastname: Noh
authors.forename: Tae-Hun
authors.initials: TH
authors.lastname: Kim
authors.forename: Jong-Suep
authors.initials: JS
authors.lastname: Baek
authors.forename: Hyoun-Hyang
authors.initials: HH
authors.lastname: Park
authors.forename: Seung S
authors.initials: SS
authors.lastname: Lee
authors.forename: Manhee
authors.initials: M
authors.lastname: Han
authors.forename: Sang-Chul
authors.initials: SC
authors.lastname: Shin
authors.forename: Cheong-Weon
authors.initials: CW
authors.lastname: Cho
mesh_terms: D000279:Administration, Cutaneous; D000328:Adult; D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology; D016503:Drug Delivery Systems; D004890:Erythema / Q000209:etiology; D006801:Humans; D008297:Male; D008845:Microinjections / Q000009:adverse effects*; D009339:Needles; D011108:Polymers; D051381:Rats; D054772:Rats, Hairless; D012867:Skin; D012869:Skin Absorption; D055815:Young Adult
chemical_list: D011108:Polymers; D001205:Ascorbic Acid