title: A facile system to evaluate in vitro drug release from dissolving microneedle arrays.
abstract: The use of biological tissues in the in vitro assessments of dissolving (?) microneedle (MN) array mechanical strength and subsequent drug release profiles presents some fundamental difficulties, in part due to inherent variability of the biological tissues employed. As a result, these biological materials are not appropriate for routine used in industrial formulation development or quality control (QC) tests. In the present work a facile system using Parafilm M(®) (PF) to test drug permeation performance using dissolving MN arrays is proposed. Dissolving MN arrays containing 196 needles (600 μm needle height) were inserted into a single layer of PF and a hermetic "pouch" was created including the array inside. The resulting system was placed in a dissolution bath and the release of model molecules was evaluated. Different MN formulations were tested using this novel setup, releasing between 40 and 180 μg of their cargos after 6h. The proposed system is a more realistic approach for MN testing than the typical performance test described in the literature for conventional transdermal patches. Additionally, the use of PF membrane was tested either in the hermetic "pouch" and using Franz Cell methodology yielding comparable release curves. Microscopy was used in order to ascertain the insertion of the different MN arrays in the PF layer. The proposed system appears to be a good alternative to the use of Franz cells in order to compare different MN formulations. Given the increasing industrial interest in MN technology, the proposed system has potential as a standardised drug/active agent release test for quality control purposes.
authors.affiliation: School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK.
authors.forename: Eneko
authors.initials: E
authors.lastname: Larrañeta
authors.affiliation: School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Stewart
authors.affiliation: School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Fallows
authors.affiliation: School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK.
authors.forename: Lena L
authors.initials: LL
authors.lastname: Birkhäuer
authors.affiliation: School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK.
authors.forename: Maeliosa T C
authors.initials: MT
authors.lastname: McCrudden
authors.affiliation: School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK.
authors.forename: A David
authors.initials: AD
authors.lastname: Woolfson
authors.affiliation: School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK. Electronic address: r.donnelly@qub.ac.uk.
authors.forename: Ryan F
authors.initials: RF
authors.lastname: Donnelly
mesh_terms: D065546:Drug Liberation; D008845:Microinjections / Q000379:methods*; D009339:Needles; D010232:Paraffin / Q000737:chemistry; D012995:Solubility; D013678:Technology, Pharmaceutical / Q000379:methods
chemical_list: D010232:Paraffin
keywords: Microneedles; Polymeric films; Quality control; Release tests; Transdermal