title: Effect of chemical enhancers and iontophoresis on thiocolchicoside permeation across rabbit and human skin in vitro.
abstract: The aim of this work was to study the permeation of thiocolchicoside across the skin in vitro. The effect of the chemical enhancer lauric acid and the physical technique of iontophoresis was investigated. Permeation experiments were performed in vitro using rabbit ear skin as barrier. The effect of lauric acid at different concentrations (2% and 4%) and of the vehicle (water, ethanol, or ethanol/water) was investigated. The primary effect of lauric acid was on the partitioning parameter, whereas the diffusive parameter did not change significantly. When human epidermis was used, the permeation parameters were generally lower, although not significantly different from rabbit ear skin. The data obtained with full-thickness human skin indicate that, despite the hydrophilic nature of thiocolchicoside, the resistance to drug transport is not limited to the stratum corneum, but that the underlying dermal tissue can also contribute. Iontophoresis enhanced the flux of thiocolchicoside compared with the passive control. The mechanism by which iontophoresis enhanced thiocolchicoside transport across the skin was electroosmosis. The permeation of thiocolchicoside across the skin can be enhanced using chemical or physical penetration enhancers.
authors.affiliation: Dipartimento Farmaceutico, University of Parma, Parco Area delle Scienze 27/A, 43100 Parma, Italy.
authors.forename: Mariella
authors.initials: M
authors.lastname: Artusi
authors.forename: Sara
authors.initials: S
authors.lastname: Nicoli
authors.forename: Paolo
authors.initials: P
authors.lastname: Colombo
authors.forename: Ruggero
authors.initials: R
authors.lastname: Bettini
authors.forename: Antonia
authors.initials: A
authors.lastname: Sacchi
authors.forename: Patrizia
authors.initials: P
authors.lastname: Santi
mesh_terms: D000277:Adjuvants, Pharmaceutic / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D003078:Colchicine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D066298:In Vitro Techniques; D007478:Iontophoresis; D007850:Lauric Acids / Q000008:administration & dosage / Q000494:pharmacology*; D009995:Osmosis; D010539:Permeability; D011817:Rabbits; D012867:Skin / Q000187:drug effects* / Q000378:metabolism; D012869:Skin Absorption / Q000187:drug effects*
chemical_list: D000277:Adjuvants, Pharmaceutic; D007850:Lauric Acids; C030358:lauric acid; D003078:Colchicine; C004280:thiocolchicoside