Extraction of amino acids by reverse iontophoresis: simulation of therapeutic monitoring in vitro.
Reverse iontophoresis across the skin has been investigated as alternative, non-invasive method for clinical and therapeutic drug monitoring. This research investigated the reverse iontophoretic extraction of 19 amino acids present at clinically relevant levels in the subdermal compartment of an in vitro diffusion cell. Over a simulated, systemic concentration range of 0-500 microM, the extraction of amino acids was linear. Charged amino acids were extracted towards the electrode of opposite polarity, while zwitterionic species were extracted to both anode and cathode with the latter predominating. The reverse iontophoretic extraction flux was a linear function of amino acid isoelectric point, reflecting the different contributions of electromigration and electroosmosis to electrotransport. Overall, the results confirm the feasibility of monitoring amino acids at clinically relevant levels and provide an incentive for in vivo research to further explore the clinical potential of reverse iontophoresis for the non-invasive monitoring of amino acids.
Sieg
Anke
A
Baxter R & D Europe, Department of Renal Solutions, Nivelles, Belgium. anke_siega@gmx.de
Jeanneret
Fabienne
F
Fathi
Marc
M
Hochstrasser
Denis
D
Rudaz
Serge
S
Veuthey
Jean-Luc
JL
Guy
Richard H
RH
Delgado-Charro
M Begoña
MB
D000596:Amino Acids / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D000818:Animals; D002853:Chromatography, Liquid; D015194:Diffusion Chambers, Culture; D016903:Drug Monitoring / Q000379:methods*; D053841:Electroosmosis; D005240:Feasibility Studies; D007478:Iontophoresis; D007526:Isoelectric Point; D013058:Mass Spectrometry; D015394:Molecular Structure; D010539:Permeability; D015203:Reproducibility of Results; D012867:Skin / Q000737:chemistry* / Q000378:metabolism; D013329:Structure-Activity Relationship; D013552:Swine; D013997:Time Factors
D000596:Amino Acids