title: Amperometric monitoring of quercetin permeation through skin membranes.
abstract: Transdermal delivery of quercetin (QR, 3,3',4',5,7-pentahydroxyflavone), a natural flavonoid with a considerable antioxidant capacity, is important for medical treatment of, e.g., skin disorders. QR permeability through skin is low, which, at the same time, makes the monitoring of percutaneous QR penetration difficult. The objective of this study was to assess an electrochemical method for monitoring QR penetration through skin membranes. An electrode was covered with the membrane, exposed to QR solution, and electrode current was measured. The registered current was due to electro-oxidation of QR penetrating the membrane. Exploiting strict current-QR flux relationships diffusion coefficient, D, of QR in skin and dialysis membranes was calculated. The D values were strongly dependent on the theoretical model and parameters assumed in the processing of the amperometric data. The highest values of D were in the range of 1.6-6.1×10(-7)cm(2)/s. This was reached only for skin membranes pretreated with buffer-ethanol mixture for more than 24h. QR solutions containing penetration enhancers, ethanol and l-menthol, definitely increased D values. The results demonstrate that electrochemical setup gives a possibility to assess penetration characteristics as well as enables monitoring of penetration dynamics, which is more difficult by traditional methods using Franz cells.
authors.affiliation: Department of Biomedical Sciences, Faculty of Health and Society, Malmö University, 205 06 Malmö, Sweden; Biofilms-Research Center for Biointerfaces, Malmö University, 205 06 Malmö, Sweden.
authors.forename: Jadwiga
authors.initials: J
authors.lastname: Rembiesa
authors.affiliation: Department of Biomedical Sciences, Faculty of Health and Society, Malmö University, 205 06 Malmö, Sweden; Biofilms-Research Center for Biointerfaces, Malmö University, 205 06 Malmö, Sweden.
authors.forename: Hala
authors.initials: H
authors.lastname: Gari
authors.affiliation: Department of Biomedical Sciences, Faculty of Health and Society, Malmö University, 205 06 Malmö, Sweden; Biofilms-Research Center for Biointerfaces, Malmö University, 205 06 Malmö, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Engblom
authors.affiliation: Department of Biomedical Sciences, Faculty of Health and Society, Malmö University, 205 06 Malmö, Sweden; Biofilms-Research Center for Biointerfaces, Malmö University, 205 06 Malmö, Sweden. Electronic address: tautgirdas.ruzgas@mah.se.
authors.forename: Tautgirdas
authors.initials: T
authors.lastname: Ruzgas
mesh_terms: D000279:Administration, Cutaneous; D000818:Animals; D016903:Drug Monitoring / Q000295:instrumentation / Q000379:methods*; D009924:Organ Culture Techniques; D010539:Permeability; D011794:Quercetin / Q000008:administration & dosage* / Q000378:metabolism*; D012869:Skin Absorption / Q000187:drug effects* / Q000502:physiology*; D013552:Swine
chemical_list: D011794:Quercetin
keywords: Diffusion coefficient; Electrochemistry; Ethanol (PubChem CID: 702); Flavonoids; Methanol (PubChem CID: 887); Penetration enhancers; Quercetin; Quercetin (PubChem CID: 5280343); Skin permeation; l-menthol (PubChem CID: 16666)