SOFT 2004 Meeting Abstracts - Society of Forensic Toxicologists

M17
CANNABINOID ANALYSIS OF ORAL FLUIDS COLLECTED FROM CLINICAL SUBJECTS
FOLLOWING ORAL TETRAHYDROCANNABINOL (THC) ADMINISTRATION (HEMP OIL
AND DRONABINOL)
William D. Darwin l *, Richard A. Gustafson 2 , Jason Sklerov 3 , Dean Fritch 4 , Aaron Jacobs\ Kristen Blum 4 ,
Sam Niedbala 4 , Eric T. Moolchan l , and Marilyn A. Huestis' : IChemistry and Drug Metabolism Section,
IRP, NIDA, NIH, 5500 Nathan Shock Drive, Baltimore, MD 21224; 2Jacksonville Naval Air Station,
Jacksonville, FL 32212; 3Armed Forces Institute of Pathology, Research Blvd., Rockville, MD 20850;
40raSure Technologies, Inc., 150 Webster Street, Bethlehem, PA 18015
Therapeutic usefulness of oral cannabinoids is being investigated to address analgesia, AIDS-wasting
disease, counteracting spasticity of motor diseases, and emesis following chemotherapy. In addition,
cannabis is among the most abused psychoactive substances. Following cannabis use, physiological and
behavioral changes occur necessitating testing to detect impairment. In recent years, food products (hemp
oil) derived from cannabis have been introduced into the U.S. Analysis of hemp oils reveals that THC is
present in a wide concentration range. If these products produce positive drug test for urine and alternate
matrices, screening programs to identify cannabis use may be affected. A clinical study to investigate the
pharmacokinetics and pharmacodynamics of oral THC was performed. The randomized, double blind,
placebo-controlled within-subject, inpatient study compared the effects of hemp oil in liquid and capsule
form to dronabinol (synthetic THC) doses consistent with therapy for appetite-stimulation. Hemp oil
dosing followed manufacturer's recommendations. Five dosing conditions (0.0, 0.39, 0.47, 7.5, and 14.8
mg/day) of oil/capsules were administered three times daily with meals for five consecutive days. One
objective was to determine if hemp oil could produce positive cannabinoid alternative matrices tests. Two
devices were used to collect oral fluids, OraSure (OraSure Technologies) and Salivette (Sarstedt) from 90­
min after the first dose to 1 day after the last dose. Salivette samples were analyzed by LCIMS.
LiquidlIiquid extractions isolated THCCOOH from ll-OH-THC and THC. Extraction efficiencies were
280%. An LCIMSD (Agilent) with an Eclipse C18 column and electrospray interface with data acquired in
the NCI mode was used for analysis. SIM ions monitored were: THCCOOH, mlz 343.2; d3-THCCOOH,
mlz 346.2; 11-0H-THC, mlz 329.2; d3-11-0H-THC, mlz 332.2; THC, m/z 313.2; and d3-THC m/z 316.2.
Limits of quantitation (LOQ) were 1.0, 0.5, and 0.5 ng/mL and limits of detection (LOD) 0.5, 0.2, and 0.2
ngimL for THCCOOH, ll-OH-THC, and THC, respectively. 511 Salivettes from 7 subjects were
analyzed. OraSure oral fluid specimens were analyzed according to manufacturer's specifications with
Cannabinoids InterceptTM MICRO-PLATE Enzyme Immunoassay (OraSure Technologies) with a 12
ngimL cutoff and confirmed by GC/MS/MS. After SPE, extracts were derivatized with HFPA/PFIP.
Extraction efficiency was 50%. THC was analyzed on a Saturn Ion Trap Quadrupole (Varian) equipped
with a 5% phenyl-methyl column. Ions monitored were: THC, mlz 492 and d3-THC, mlz 495 (parent
ions); THC, m/z 238 and d3-THC, m/z 238 (product ions). LODILOQ for THC were 0.75 ngimL. 497
OraSures from 8 subjects were analyzed. All Salivette and OraSure oral fluid specimens were negative at
the specified cutoffs. In contrast, several authors reported cannabinoid positive results for Salivette and
OraSure oral fluid samples after smoked THC (Samyn, J Forensic Sci, 2002, 47: 1380; Niedbala, JAT,
2001,75:289). In addition, Niedbala found positive tests for OraSure oral fluid samples collected after oral
THC (20-25 mg THC-laced brownie), but concentrations were low ('5.7 ngimL). THC is well absorbed, but
has low bioavailability «20%) via the oral route. There is evidence that deposition ofTHC into oral fluid
is via direct sequestering into oral mucosa during drug use with minimal contribution from blood to oral
fluid (Hawks, The Cannabinoids, Academic Press, 1983, 8). Characterization of rates of absorption and
elimination of orally administered THC with different vehicles (flax oil, sesame seed oil, cookies/brownies,
and emulsions) and with direct administration and encapsulation have shown variable absorption ofTHC.
Little data have been published about oral fluid drug levels after oral THC administration; questions remain
including the degree of absorption inherent to the collection devices and THC contamination of the oral
cavity immediately following hemp oil/capsule administration. The fact that all oral fluid specimens
collected were negative with two different devices for THC-containing hemp oils and capsules suggests
little contamination of the oral fluid following ingestion of dronabinol or hemp oils by the time the first
specimen was collected, at least by 90 minutes after dosing.
Keywords: OraSure, Salivette, Oral Administration ofTHC
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