PURPOSE: To investigate the transdermal delivery of a model macromolecule by passive and iontophoretic means following pretreatment with C12-penetration enhancers and to visualise transport across human stratum corneum (SC) in real time. METHODS: Transport studies of dextran, labelled with fluorescent Cascade Blue (D-CB: M(R) = 3 kDa) across human stratum corneum, were conducted during passive and iontophoretic modes of delivery following pretreatment with either dodecyltrimethylammonium bromide (DTAB), sodium dodecyl sulphate (SDS) or Azone. Size-exclusion chromatography was used to assess maintenance of dextran structural integrity throughout experimental lifetime. Two-photon excitation microscopy was employed to visualise real-time dextran transport during current application. RESULTS: The positively charged C12-enhancer DTAB elevated passive D-CB steady-state flux (J(ss)) and was the only enhancer to do so above control during iontophoresis. The negatively charged SDS had the least effect during both stages. On-line macromolecular transport was visualised, indicating both inter- and intra-cellular pathways across SC during current application. No transport was visible across untreated SC during passive transport. CONCLUSIONS: Use of a positively charged enhancer may improve J(ss) of anionic macromolecular penetrants during passive and iontophoretic delivery. On-line visualisation of iontophoresis across SC was possible and can provide mechanistic insight into SC transport pathways.
PURPOSE: To investigate the transdermal delivery of a model macromolecule by passive and iontophoretic means following pretreatment with C12-penetration enhancers and to visualise transport across human stratum corneum (SC) in real time. METHODS: Transport studies of dextran, labelled with fluorescent Cascade Blue (D-CB: M(R) = 3 kDa) across human stratum corneum, were conducted during passive and iontophoretic modes of delivery following pretreatment with either dodecyltrimethylammonium bromide (DTAB), sodium dodecyl sulphate (SDS) or Azone. Size-exclusion chromatography was used to assess maintenance of dextran structural integrity throughout experimental lifetime. Two-photon excitation microscopy was employed to visualise real-time dextran transport during current application. RESULTS: The positively charged C12-enhancer DTAB elevated passive D-CB steady-state flux (J(ss)) and was the only enhancer to do so above control during iontophoresis. The negatively charged SDS had the least effect during both stages. On-line macromolecular transport was visualised, indicating both inter- and intra-cellular pathways across SC during current application. No transport was visible across untreated SC during passive transport. CONCLUSIONS: Use of a positively charged enhancer may improve J(ss) of anionic macromolecular penetrants during passive and iontophoretic delivery. On-line visualisation of iontophoresis across SC was possible and can provide mechanistic insight into SC transport pathways.
Authors: Grace Tan; Peng Xu; Louise B Lawson; Jibao He; Lucia C Freytag; John D Clements; Vijay T John Journal: J Pharm Sci Date: 2010-02 Impact factor: 3.534
Authors: Ana-Maria Pena; Xueqin Chen; Isaac J Pence; Thomas Bornschlögl; Sinyoung Jeong; Sébastien Grégoire; Gustavo S Luengo; Philippe Hallegot; Peyman Obeidy; Amin Feizpour; Kin F Chan; Conor L Evans Journal: Adv Drug Deliv Rev Date: 2020-03-23 Impact factor: 15.470
Authors: Marcelo B Dohnert; Mirelli Venâncio; Jonathann C Possato; Rodrigo C Zeferino; Luciana H Dohnert; Alexandra I Zugno; Cláudio T De Souza; Marcos M S Paula; Thais F Luciano Journal: Int J Nanomedicine Date: 2012-03-26