1: Eur J Pharm Biopharm. 2008 Aug;69(3):1077-82. Epub 2008 Feb 20.

Non-invasive diagnosis and monitoring of chronic kidney disease by reverse
iontophoresis of urea in vivo.

Wascotte V, Rozet E, Salvaterra A, Hubert P, Jadoul M, Guy RH, Préat V.

Université Catholique de Louvain, Unité de Pharmacie Galénique, Brussels,
Belgium.

BACKGROUND: Reverse iontophoresis uses a small current to extract molecules and
ions through the skin. The aim of the study was to determine whether reverse
iontophoresis of urea can be used (i) to diagnose and monitor non-invasively
chronic kidney disease (CKD), and (ii) to track urea levels closely during a
hemodialysis session. METHODS: A current of 0.8mA was applied for 2h in 10
healthy volunteers, in 9 patients with CKD, and in 10 patients undergoing
hemodialysis. Urea fluxes extracted by reverse iontophoresis and urea
concentrations in the blood were measured. RESULTS: Extracted urea fluxes
discriminated healthy volunteers from patients with CKD within 90 min. A
non-invasive measure of blood urea concentrations can be achieved after 120 min. 
A urea reservoir in the skin interferes with the extraction and a
pre-hemodialysis "depletion" period is required. Mild and transient sensation and
erythema induced by iontophoresis were significantly lower in the CKD group.
Gelling the formulation of the iontophoresis reservoir gave similar results to
those obtained when using a simple aqueous solution. CONCLUSIONS: Reverse
iontophoresis can be used to non-invasively diagnose individuals with CKD and to 
monitor urea concentrations in blood.


PMID: 18406585 [PubMed - indexed for MEDLINE]

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