Comparison of ORALscreenTM System for Point-of-Collection Screening of Drugs of Abuse in Oral Fluid and a Laboratory-Based Urine Screening Test
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ORALscreenTM Saliva Based Drug Test
Cannabinoids(THC), Cocaine(COC), Opiates(OPI), Methamphetamine(MET)
ABSTRACT:
This paper summarizes the results to date from
field evaluations of the ORALscreen™ System for screening of drugs in oral fluid. The ORALscreen™ System consists of an oral fluid collection device
and a test device containing a lateral flow membrane immunoassay system.
Results from the ORALscreen™ System
that were collected in the field were compared to results obtained from a urine
screening test conducted in a licensed laboratory. Results demonstrate that the
ORALscreen™ System has very good percent agreement with the
laboratory-based urine screening test results for the detection of cocaine and
opiates through 2.5 to 3 days following drug use, respectively. TNC was
detected by ORALscreen™ on the day of use and one day
after use. Good correlation between urine and oral fluid screening results was
observed for the methamphetamine positive samples, however, the number of days
following drug use was unknown because the donors did not self report use of
methamphetamine.
INTRODUCTION:
Drug testing is being carried out increasingly in
abuse/rehabilitation clinics, law enforcement agencies, and employer screening
programs. Testing for drugs of abuse is usually performed using a urine sample,
which is sent to a licensed laboratory. Alternately, point-of-collection urine
tests are conducted. In order to ensure the urine is not adulterated, directly
observed collection should be performed, but this is done only in the military
and in some criminal programs. Additionally, special facilities are required
for collection of urine samples. As legal challenges to the validity of
urinalysis increase, Chain of Custody issues are becoming very important. There
must be complete certainty that the urine sample was collected from the
individual, that the individual's identity was verified, that the sample was
unadulterated, that the sample was sealed in the donor's presence, that the
seal was not broken prior to receipt at the laboratory, and that the laboratory
analyzed and reported the results for the correct sample. The ORALscreen™ System eliminates many of these issues, by providing a drug screen
result at the site, using an observed sample collection protocol.
Oral fluid has been demonstrated to be a valid
matrix for the detection of drugs of abuse (1,2,3). ORALscreen™ is used for
point-of-collection screening of drugs of abuse in oral fluid. The oral fluid
collection is directly observed without embarrassment, without the possibility
of sample adulteration, and without special facilities. With ORALscreen™ it
takes only 15 minutes to obtain a drug screen result, in contrast to
laboratory-based urine testing which takes at least 2 days. In addition, no
special instruments or reagents are required to run the ORALscreen™ test.
ORALscreen™ THC/COC/OPI/MET is an easy to use collection
and immunoassay system intended for use in the highly sensitive, qualitative
analysis for use of the following drugs and their metabolites in human oral
fluid: cannabinoids (code THC), cocaine (code COC), opiates (code OPI), and
d-methamphetamine (code MET). MDMA, or Ecstasy, is also detected by the
methamphetamine assay. The ORALscreen™ System is based on a lateral flow
membrane immunoassay technique and contains an internal procedural control for
quality control purposes (4). The ORALscreen™ System is currently intended to
be used by trained individuals for forensic use only.
METHODS:
ORALscreen™ THC/COC/OPI/MET was evaluated in field
trials at inpatient substance abuse clinics in
Volunteers completed an interview in which they
were asked what they have had in their mouth in the last 30 minutes, what
prescription and over-the-counter drugs they have had in the last 2 days, and
what drugs of abuse they have had recently, when taken, and the mode of use.
The volunteers from the
The study
protocol involved the collection of a urine sample and the observed collection
of an oral fluid sample using the ORALscreen™ Oral Fluid Collector. The oral
fluid sample was tested at the point of collection by ORALscreen™. The urine
was analyzed by a urine screening test at a licensed laboratory. Urine
specimens found to be positive by the screening test were then analyzed by
GC-MS.
RESULTS:
Correlation Studies
The urine samples from the
Donors from the Florida site self reported THC use
the day before samples were collected and the day that samples were collected;
opiate use the day before samples were collected and the day that samples were
collected; and cocaine use up to 2.5 days before samples were collected and
through the day that samples were collected. No donors from either the
Percent
agreement between results for the different test methods and matrices was
determined as defined below:
Percent
agreement for positive samples = (PP/(PP+PN)) x 100
Percent
agreement for negative samples = (NN/(NN + NP)) x 100
Reference
method
Test method |
|
+ |
- |
+ |
PP |
NP |
|
- |
PN |
NN |
The
reference method is the lab-based screening assay for urine.
The test method is ORALscreen™, point-of-collection screening system for oral
fluid.
PP = positive by both the reference method and the test method
PN
= positive by the reference method and negative by the test method
NN = negative by both the reference method and the test method
NP
= negative by the reference method and positive by the test method
The percent agreement of the ORALscreen™ results
compared to The lab-based urine screening results for both urine positives and
negatives are shown in Table 1. Sufficient numbers of THC and COC positiveswere not obtained from either the
Table 1. Percent Agreement of ORALscreen™ Results with
Lab-Based Urine Screening Results.
Drug Group |
Site |
% Agreement w/ Urine Positive Samples |
Total N° of samples in the set for calculation of agreement w/ positive |
% Agreement w/ Urine Negative Samples |
Total N° of samples in the set for calculation of agreement w/ negative |
COC |
FL |
96% |
26 |
92% |
65 |
OPI |
FL |
100% |
23 |
99% |
68 |
OPl |
MA |
94% |
47 |
86% |
l4 |
MET |
CA |
86% |
7 |
94% |
50 |
THC |
FL |
43% |
37 |
76% |
54 |
Overall |
|
84% |
140 |
89% |
251 |
Notes:
FL =
ORALscreen™ Detection Window
Compared to Urine Results for Opiates
To allow for an estimation of the detection window of ORALscreen™ compared to
urine screening results, the
Table 2. Percent Agreement of ORALscreen™ Results with Lab-Based Urine
Screening Results for Opiates by Days Following Drug Use.
Days Following Drug Use |
% Agreement with Urine Positive Samples |
Total N° of samples in the set for calculation of agreement with positive |
% Agreement with Urine Negative Samples |
Total N° of samples in the set for calculation of agreement with negative |
0 |
100% |
5 |
Not determined |
Not determined |
1 |
96% |
26 |
100% |
1 |
2 |
88% |
8 |
100% |
4 |
3 |
80% |
5 |
50% |
2 |
Overall |
94 % |
47 |
86% |
14 |
Laboratory Studies of Potentially Interfering and Cross-Reactive Drugs
In order to determine if potentially cross-reactive
drugs interfered with the ORALscreen™ test results, compounds were dissolved in
an artificial oral fluid solution which contained no drugs or contained drugs
at the concentrations listed: morphine at 60 ng/ml, benzoylecgonine ( BE, a
cocaine metabolite) at 75 ng/ml, carboxy THC (11-nor-9-carboxy-delta-9-THC) at
600 ng/ml, and d-methamphetamine at 90 ng/ml. The compounds were initially
tested at 50 ug/ml. If a substance had an effect on the expected test result,
that substance was diluted and tested until the concentration was found that
did not have an effect on the expected results. Non-interfering compounds are
listed in Table 3.
Table 3. Non-Interfering
Compounds: At 50 ug/ml, the following compounds did not affect the expected
results for either the drug negative or drug positive samples.
acetaminophen |
acetylsalicylic acid |
aminopyrine |
amobarbital |
aspartame |
buprenorphine |
butabarbital |
caffeine |
carbamazepine |
chloropromazine |
chloroquine |
desipramine |
dextromethorphan |
diazepam |
10-11-dihydrocarbamazepine |
5,5-diphenylhydantoin |
1-ephedrine |
ibuprofen |
imipramine |
lidocaine |
LSD |
mephentermine |
methadone |
methaqualone |
PEMA |
pentobarbital |
phencyclidine (PCP) |
phenobarbital |
d,l-phenylpropanolamine |
primidone |
propoxyphene (Darvon) |
d,l- pseudoephedrine |
quinine |
secobarbital |
tetracycline |
tetrahydrozoline |
Potentially cross-reactive drugs were tested in the
laboratory by preparing pure standards at known concentrations in an artificial
oral fluid solution. Table d lists the lowest concentration tested that yielded
a drug positive test result.
Table 4. Cross-reactive
Compounds.
Compound |
Cross-reactive with |
Lowest concentration tested that yielded positive
result |
codeine |
OPI |
5 ng/rnl |
MAM |
OPI |
5 ng/ml |
naloxone |
OPl |
400 ng/m1 |
meperidine |
OPI |
12.5 ug/mI |
procaine |
OPI |
12.5 ug/ml |
atropine |
OPI |
25 ug/ml |
benzoylecgonine (BE) |
COC |
l 5 ng/ml |
carboxy THC |
THC |
350 ng/ml |
MDMA |
MET |
50 ng/ml |
MDA |
MET |
>60 ug/ml |
MDEA |
MET |
2000 ng/ml |
d-amphetamine |
MET |
53 ug/ml |
d-ephedrine |
MET |
25 ug/ml |
Notes:
MAM = monoacetylmorphine
MDMA = methylenedioxymethamphetamine (Ecstasy) MDA = methylenedioxyamphetamine
MDEA
= methylenedioxyethylamphetamine
Food/Drink
Interference
Controlled laboratory studies conducted to determine
the effect of consumption of certain foods and drinks showed that the items
listed in Table 5 did not interfere with the ORALscreen™ test result.
Foods/drinks were selected because of low pH, high alcohol content, or common
ingestion.
Consumption of lemon-poppy seed quick bread
rendered a positive opiate test result. It is recommended that if a positive
opiate result is obtained for a donor who claims ingestion of poppy seeds that
another ORALscreen™ test be run approximately I hour after the initial test.
Poppy seeds should not interfere with the test result one hour after
consumption.
Table 5. Consumed
foods/drinks that did not interfere with ORALscreen™ result.
Coffee with skim milk |
Hot tea with skim milk |
Toothpaste |
Orange soda |
Diet cola |
Cranberry/apple juice |
Apple juice |
Lemonade |
Pickles |
Sour fruit candy |
Bubble gum |
Beer |
Listerine © mouthwash, 26.9% alcohol |
Poppy seed salad dressing |
Precision
A study was conducted
to determine the precision for the ORALscreen™ Cannabinoids (THC), Cocaine
(COC), Opiates (OPI), Methamphetamine (MET) system. In this study four prepared
samples of known drug concentration were loaded onto the test device using an
oral fluid collector. The results were then interpreted and recorded. Each
sample was run 4 times daily (
The prepared samples for this study were made using an artificial oral fluid formulation. Drug positive samples were prepared using carboxy T}IC, benzoylecgonine (BE, a cocaine metabolite), morphine, and d-methamphetamine. A pane) of four samples was prepared that included the following drug concentrations: drug negative, 50 % above and below the cutoff, and at the cutoff. No trends were observed for any control or drug line, for any sample set, for either AM or PM analyses, or for results over time for the 20 assay days. Percent agreement to the expected result was determined and is shown in Table 6. Agreement averaged 95 % across the four drugs for the sample SO % below cutoff; averaged 92 % across the four drugs for the sample at the cutoff values, and averaged 99 % across the four drugs for the sample 50 % above the cutoff: The percent agreement for the negative sample was 100 % for all four drugs throughout the study.
Table 6. Precision: Overall percent agreement to the expected result for 20 assay days for each drug and averaged across the 4 drug groups:
Sample |
THC |
COC |
OPI |
MET |
%
AVG |
Negative |
100% |
100% |
100% |
100% |
100% |
50% below cutoff |
99% |
95% |
86% |
100% |
95% |
At the cutoff |
80% |
98% |
99% |
91% |
92% |
50% above cutoff |
96% |
100% |
100% |
98% |
99% |
SUMMARY
The ORALscreen™ System is an easy to use collection and immunoassay system intended for use in the highly sensitive, qualitative analysis for use of cannabinoids, cocaine and metabolites, opiates, and methamphetamines (including MDMA) in human oral fluid. The results collected in this field evaluation have shown very good performance of the ORALscreen™ System compared to a laboratory-based urine screening test for the detection of cocaine and opiates through 2.5 to 3 days following drug use, respectively. THC was detected by ORALscreen™ on the day of use and one day after use. Good correlation between urine and oral fluid screening results was observed for the methamphetamine positive samples, however, the number of days following drug use was unknown because the donors did not self report use of methamphetamine. Advantages of the ORALscreen™ System over a laboratory-based urine screening test include: results obtained at the point-of-collection in minutes rather than days later from the laboratory, no need for special collection facilities, observed sample collection, no possibility of sample adulteration, and no special laboratory equipment or reagents are required.
References:
l. Kidwell, D_A.,
2. Jenkins, A.J., Oyler,
J.M. and Cone, E_J. Comparison of lleroin and Cocaine
Concentrations in Saliva with Concentrations in Blood and Plasma. J. Anal.
Toxicology. 19: 359-374 (1995).
3. Cone, E.J. Saliva Testing for Drugs of
Abuse. Malamud, D., Tabak,
L., eds. Saliva as a Diagnostic Fluid. Annals NY Acad
Sci. 694: 91-127 (1993).
4. Sun, M.
and Pfeiffer, F.R., "Analytical Test Device for Competition Assay for
Drugs of Non-Protein Antigens Using lmmunocluomatographic
Techniques," US. Patent #5,2238,652
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