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Percutaneous Absorption and Pharmacokinetics of Eflornithine HC®l 13.9% Cream in Women with Unwanted Facial Hair
Author(s) -
Malhotra Bimal,
Noveck Robert,
Behr Douglas,
Palmisano Maria
Publication year - 2001
Publication title -
the journal of clinical pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.92
H-Index - 116
eISSN - 1552-4604
pISSN - 0091-2700
DOI - 10.1177/009127000104100907
Subject(s) - eflornithine , pharmacokinetics , medicine , urine , pharmacology , chemistry , biochemistry , ornithine decarboxylase , enzyme
This article reports the results of an open‐label, multiple‐dose study to determine percutaneous absorption and pharmacokinetics of eflornithine following topical treatment with eflornithine HC®l 13.9% cream (Vaniqa™). Ten women with excessive facial hair were treated with two 0.5 g single doses of [ 14 C]‐labeled eflornithine HC®l 13.9% (w/w) cream (periods A and C) separated by twice‐daily application of 0.5 g unlabeled eflornithine HC113.9% cream for 7 days (period B). Analysis of radioactivity excreted in urine and feces indicated that percutaneous absorption was minimal. Comparison with urinary excretion of eflornithine in period A suggested that most of absorbed eflornithine was excreted in urine without being metabolized. Radioactivity was not detectable in blood or plasma, but eflornithine concentrations were measurable, with peak concentrations of 4.96 ng/ml in period A and 10.44 ng/ml in period C. Eflornithine was eliminated from plasma with a mean terminal half‐life of 11 hours (first application) and 8 hours (final application). Trough plasma concentrations reached steady state (4.61‐5.50 ng/ml) after 4 days of twice‐daily topical treatment, and multiple dosing had no apparent effect on disposition kinetics. The low degree of percutaneous absorption and low systemic exposure to eflornithine offer a favorable clinical safety profile of eflornithine HC®l 13.9% cream.