Iontophoretic permselectivity of mammalian skin: characterization of hairless mouse and porcine membrane models

Asteria Luzardo-Alvarez, Monica Rodríguez-Fernández, José Blanco-Méndez, Richard H. Guy, M. Begoña Delgado-Charro

Research output: Contribution to journalArticle

36 Citations (Scopus)


Purpose. To evaluate the transport number of Na+, and the isoelectric point, of two skin membranes frequently used for iontophoretic in vitro research. Methods. Na+ transport numbers were determined by the Hittorf method or by the measurement of membrane potential. The skin isoelectric point was deduced from the electroosmosis of mannitol (a polar non-electrolyte) as a function of pH. Results. The Na+ transport number across porcine skin, like that for hairless mouse, indicated a modest cation permselectivity. Consistent with this observation, the isoelectric points of porcine and hairless mouse skin were determined to be in the ranges of 3.5-3.75 and 4.5-4.6, respectively. That is, at physiological pH, both of these model membranes supports a net negative charge. Conclusions. The permselective properties of porcine and hairless mouse skin are similar (but with the porcine membrane having apparently fewer basic or more weakly-acidic groups than that of the mouse) and consistent with the characteristics, which have been deduced elsewhere, of human skin.

Original languageEnglish
Pages (from-to)984-987
Number of pages4
JournalPharmaceutical Research
Issue number7
Publication statusPublished - Jul 1998



  • Electroosmosis
  • Iontophoresis
  • Mannitol
  • Permselectivity
  • Skin isoelectric point
  • Transdermal delivery

Cite this