title: Bioceramic microneedles with flexible and self-swelling substrate.
abstract: To reduce the effort required to penetrate the skin and optimize drug release profiles, bioceramic microneedle arrays with higher-aspect-ratio needles and a flexible and self-swelling substrate have been developed. Swelling of the substrate can assist in separating it from the needles and leave them in the skin as a drug depot. The preparation procedures for this bioceramic microneedle are described in the paper. Clonidine hydrochloride, the model drug, was released in a controlled manner by the microneedle device in vitro. Results showed that the microneedle array with a flexible and self-swelling substrate released the drug content faster than the array with a rigid substrate. Disintegration of the needle material and diffusion of the drug molecules are believed as the main control mechanisms of the drug release from these microneedle arrays. Ex vivo skin penetration showed that they can effectively penetrate the stratum corneum without an extra device. This work represents a progression in the improvement of bioceramic microneedles for transdermal drug delivery.
authors.affiliation: Division for Applied Materials Science, Department of Engineering Sciences, The Ångström Laboratory, Uppsala University, Box 534, SE-751 21 Uppsala, Sweden.
authors.forename: Bing
authors.initials: B
authors.lastname: Cai
authors.affiliation: Division for Applied Materials Science, Department of Engineering Sciences, The Ångström Laboratory, Uppsala University, Box 534, SE-751 21 Uppsala, Sweden. Electronic address: Wei.Xia@angstrom.uu.se.
authors.forename: Wei
authors.initials: W
authors.lastname: Xia
authors.affiliation: Division for Applied Materials Science, Department of Engineering Sciences, The Ångström Laboratory, Uppsala University, Box 534, SE-751 21 Uppsala, Sweden.
authors.forename: Susanne
authors.initials: S
authors.lastname: Bredenberg
authors.affiliation: Otolaryngology and Head & Neck Surgery, Department of Surgical Sciences, Uppsala University, Akademiska sjukhuset 78-79, 75185 Uppsala, Sweden.
authors.forename: Hao
authors.initials: H
authors.lastname: Li
authors.affiliation: Division for Applied Materials Science, Department of Engineering Sciences, The Ångström Laboratory, Uppsala University, Box 534, SE-751 21 Uppsala, Sweden.
authors.forename: Håkan
authors.initials: H
authors.lastname: Engqvist
mesh_terms: D000818:Animals; D002516:Ceramics / Q000737:chemistry*; D003000:Clonidine / Q000008:administration & dosage / Q000493:pharmacokinetics; D016503:Drug Delivery Systems / Q000295:instrumentation* / Q000379:methods; D065546:Drug Liberation; D004867:Equipment Design; D066298:In Vitro Techniques; D008845:Microinjections / Q000295:instrumentation* / Q000379:methods; D009339:Needles; D012867:Skin / Q000187:drug effects / Q000378:metabolism; D013552:Swine
chemical_list: D003000:Clonidine
keywords: Bioceramics; Clonidine; Controlled-release; Microneedles; Skin penetration