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
Massachusetts and Florida and by a probation department in California. Volunteers were asked to participate in the study and signed a consent form.

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
California site did not self report use of drugs of abuse.

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 Massachusetts and Florida sites were analyzed by two lab-based screening methods: EMIT for THC, cocaine metabolite, and opiates and by CED1A DAU Amphetamines for methamphetamine. The urine samples from the California site were analyzed by a lab-based EIA method. Cutoff levels for the urine screening tests were 300ng/ml for morphine, 300 ng/ml for BE (benzoylecgonine, a metabolite of cocaine), 50 ng/ml for carboxy THC (11-nor-9-carboxy-delta-9-THC), and 1000 ng/ml for d­methamphetamine. The lab-based screening assay urine positives were further analyzed by urine GC-MS confirmation assays. There was excellent correlation between the urine screening results and the urine confirmation results as 95 % or greater of the screening positives were confirmed by GC-MS.

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
Florida or Massachusetts sites self reported use of methamphetamine. Donors from the California site did not self report use of drugs of abuse.

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 Massachusetts or California sites to be included in the calculations. No methamphetamine users participated in the studies in Florida or Massachusetts. The percent agreement values were very good for both the positive set and the negative set, averaging 84 % and 89 %, respectively, across all four drug groups. Results from this study demonstrate that the ORALscreen™ System has a very good correlation with lab-based screening assays for urine. The lower correlation for THC positives may be related to the shorter detection window of THC and metabolites in oral fluid versus the longer detection window typically displayed in urine.

 

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 = Florida MA = Massachusetts  CA = California

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 Massachusetts site data was sorted according to days following self reported drug use. 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 2. Day 0 indicates that self reported use occurred on the same day that the samples were collected, day 1 indicates that self reported use occurred the day before samples were collected, etc. The overall value includes data for donors self reporting no drug use, as well as for donors self reporting use 7 and 13 days prior to sample collection and for donors who did not reply to the question. The data shows very good correlation between the ORALscreen™ and tab-based urine screening results for opiate use up to 3 days before the samples are collected. Sufficient numbers of samples were not collected beyond 3 days following use to determine percent agreement values


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 (2 am runs and 2 pm runs) for 20 working days to obtain 80 values per sample.

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., Holland, J.C., Athanaselis, S. Testing for Drugs of Abuse in Saliva and Sweat. J. of Chrom. B. 713: 111-135 (1998).
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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