TY - JOUR
T1 - Transdermal drug delivery by coated microneedles: Geometry effects on effective skin thickness and drug permeability
AU - Davidson, A
AU - Al-Qallaf, B
AU - Das, D B
N1 - ID number: 000260693700002
PY - 2008
Y1 - 2008
N2 - Although transdermal drug delivery has been used for about three decades, the range of therapeutics that are administered this way is limited by the barrier function of the stratum corneum (the top layer of skin). Microneedle arrays have been shown to increase the drug permeability in skin by several orders of magnitude by bypassing the stratum corneum. This can potentially allow the transdermal delivery of many medicaments including large macromolecules that typically cannot diffuse through the skin. This paper addresses the use of microneedles coated with a drug solution film. In particular, we identify how the geometries of various microneedles affect the drug permeability in skin. Effective skin permeability is calculated for a range of microneedle shapes and dimensions in order to identify the most efficient geometry. To calculate effective permeability (P-eff), the effective skin thickness (H-eff) is calculated. These are then plotted for insulin as a model drug to see how various microneedle parameters affect the profiles of both H-eff and P-eff. It is found that the depth of penetration from the microneedle array is the most important factor in determining P-eff, followed by the microneedle spacings. Other parameters such as microneedle diameter and coating depth are less significant. (C) 2008 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
AB - Although transdermal drug delivery has been used for about three decades, the range of therapeutics that are administered this way is limited by the barrier function of the stratum corneum (the top layer of skin). Microneedle arrays have been shown to increase the drug permeability in skin by several orders of magnitude by bypassing the stratum corneum. This can potentially allow the transdermal delivery of many medicaments including large macromolecules that typically cannot diffuse through the skin. This paper addresses the use of microneedles coated with a drug solution film. In particular, we identify how the geometries of various microneedles affect the drug permeability in skin. Effective skin permeability is calculated for a range of microneedle shapes and dimensions in order to identify the most efficient geometry. To calculate effective permeability (P-eff), the effective skin thickness (H-eff) is calculated. These are then plotted for insulin as a model drug to see how various microneedle parameters affect the profiles of both H-eff and P-eff. It is found that the depth of penetration from the microneedle array is the most important factor in determining P-eff, followed by the microneedle spacings. Other parameters such as microneedle diameter and coating depth are less significant. (C) 2008 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
UR - http://www.scopus.com/inward/record.url?scp=53249119663&partnerID=8YFLogxK
UR - http://dx.doi.org/10.1016/j.cherd.2008.06.002
U2 - 10.1016/j.cherd.2008.06.002
DO - 10.1016/j.cherd.2008.06.002
M3 - Article
SN - 0263-8762
VL - 86
SP - 1196
EP - 1206
JO - Chemical Engineering Research & Design
JF - Chemical Engineering Research & Design
IS - 11A
ER -