SOFT 2004 Meeting Abstracts - Society of Forensic Toxicologists

MSl
DISPOSITION OF COCAINE AND METABOLITES IN HUMAN SWEAT FOLLOWING
CONTROLLED COCAINE ADMINISTRATION
Sherri L. Kacinkol*, Allan J. Barnes l , Eugene W. Schwilke 1 , Jonathan M. Oyler 2 , Edward J. Cone\ Eric T.
Moolchan\ and Marilyn A. Huestis l : IChemistry and Drug Metabolism Section, Intramural Research
Program, NIDA, NIH, 5500 Nathan Shock Drive, Baltimore, MD 21224; 2Department of the Army, US
Army Research, Development and Engineering Command, 5183 Blackhawk Road, Aberdeen Proving
Ground, MD 21010 ; 3ConeChem Research, LLC. 441 Fairtree Drive, Serverrna Park, MD 21146
The analysis of sweat for drugs of abuse offers a convenient, non-invasive technique for monitoring drug
exposure. Sweat can be collected using the Pharmchek® Sweat Patch; an absorbent cellulose pad with
adhesive backing that is worn on the body. The comparison of sweat test results to urinalysis indicates that
sweat may be an acceptable matrix for drugs of abuse screening for drug treatment, criminal justice, and
employment screening purposes.
Healthy volunteers (n=8), with a history of cocaine (COC) use, provided informed consent to participate in
this IRB approved research study and resided on the closed ward throughout the 12-week study. After an
initial three-week washout period, volunteers received 3 low dose (15 mg/10 kg) subcutaneous injections of
cocaine HCI on every other day and, three weeks later, 3 high doses (150 mgl10 kg).
Pharmchek® Sweat Patches collected for up to 48 hours following the first low (n=82) and high (n=18)
doses were isolated for cocaine and eleven metabolites by solid phase extraction and analyzed by GCIEI­
MS. LOD and LOQ were 2.5 ng/patch for COC, ecgonine methyl ester (EME), benzoylecgonine (BE) and
meta- and para-hydroxycocaine (m- poOH-COC)o
COC was the primary analyte detected in patches worn for 1-15 hours after the first low (26 of 82, 32%
positive patches) and high (36 of18, 46% positive patches) doses. COC Cmax ranged from 6-64 ng/patch
and 5-315 ng/patch following low and high doses, respectively. Not only was there large variability in
Cmax, but there also was wide variability for the time of Cmax. Several patches (2 of 21 for low dose and
6 of 26 for high dose) worn for four or less hours were positive for COC 24-48 hours after administration.
Half of the participants had positive COC results for both low and high dose sweat patches applied 32
hours after dose and worn for 15 hours, demonstrating improved detection in patches worn for extended
periods.
EME was detected in sweat patches collected from 3 participants after low dose (1% positive patches) and
4 participants after the high dose (13% positive patches) and was detected only in patches collected for the
first 24 hours after dosing. Maximum EME concentrations ranged from 8-41 ng/patch and 5-51 ng/patch
for the low and high dose, respectively. BE was detected in 6% of the low and 8% of the high dose patches.
with concentration ranges of 5-13 ng/patch after low dose and 6-12 ng/patch after high dose. One
participant had a positive m-OH-COC patch (3 ng/patch) after high dose administration. In addition, m­
and p-OH-COC were detected concurrently in the 2-4 hour (3 ng/patch m-OH-COC, 6 ng/patch p-OH­
COC) and 8-23 hour (3 ng/patch m-OH-COC and 5 ng/patch p-OH-COC) patches collected from one
participant after the high dose.
COC, BE and EME can be detected within 2 hours of drug administration but there is wide intra- and intersubject
variability in the amount detected and the time at which Cmax is reached. During the 24 hours after
exposure COC can be detected in patches worn for short periods (1-2 hours) but after 24 hours the patch
must be worn for longer periods to detect COCo EME was detected more often and at higher
concentrations than BE; both were detected only within the first 24 hours after exposure.
Sweat testing for COC and BE has been proposed by the Substance Abuse and Mental Health Services
Administration for federally-mandated workplace drug testing with patches worn for 1-14 days. In this
study patches were only worn for 15 hours. It should be noted, however, that EME was detected more
frequently and at higher concentrations than BE.
Keywords: Cocaine, Sweat, Controlled Cocaine Administration
Page 334