On the dermal absorption of cocaine.
A 5-mg dose of cocaine free base applied to the volar forearm skin surface of a volunteer resulted in a maximal urinary benzoylecgonine concentration of 55 ng/mL at 48 h, using discrete urine specimens. A total of 58 micrograms of benzoylecgonine, representing 1.2% of the dose, was excreted in the 96-h urine. An identical trial using 5 mg of cocaine hydrochloride resulted in a maximal urinary benzoylecgonine concentration of 15 ng/mL at 24 h. We conclude that dermal absorption of cocaine represents a minor, but significant route of exposure to this drug that needs to be considered when interpreting low-level urine drug testing results.
Baselt
R C
RC
Chemical Toxicology Institute, Foster City, California 94404.
Chang
J Y
JY
Yoshikawa
D M
DM
D000328:Adult; D003042:Cocaine / Q000031:analogs & derivatives / Q000493:pharmacokinetics* / Q000652:urine; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006801:Humans; D008297:Male; D011863:Radioimmunoassay; D012867:Skin / Q000378:metabolism*; D012869:Skin Absorption; D013997:Time Factors
C005618:benzoylecgonine; D003042:Cocaine