It’s been known for a long time that drugs of abuse can be detected in sweat. However, until the PharmChek® Sweat Patch was developed, there was no convenient, consistent way to collect the sweat for analysis.
The PharmChek® Sweat Patch is similar to a large band aid designed as a collector for non-volatile components of sweat including drugs of abuse. PharmChek® consists of an adhesive plastic film that holds an absorbent pad in place against the skin. The adhesive film of the patch is a semi-permeable membrane that allows oxygen, carbon dioxide, and water vapor to pass through so that the skin can breathe normally. Larger molecules, such as drugs, are trapped in the absorbent pad of the patch. Contaminants from the environment cannot penetrate the adhesive barrier from the outside, so the patch can be worn during normal activities.
How It's Made
The outside layer of the PharmChek® Sweat Patch consists of a transparent, polyurethane film that is held to the skin by a hypoallergenic adhesive. The film and the adhesive are manufactured by 3M with the same surgical adhesive used in hospitals.
The absorption pad, housed under the transparent film, is the portion that collects the sweat components and is also the only portion of the Sweat Patch that is tested by the laboratory for the presence of drugs.
Between the adhesive and the absorbent pad is the release liner that allows the absorbent pad to be removed from the Sweat Patch easily after the patch is worn.
Each PharmChek® Sweat Patch has a unique I.D. number printed on the underside of the transparent film. This unique I.D. number is the number used to track the Sweat Patch on the chain of custody form.
PharmChek® is designed to collect the components of sweat, including drugs of abuse. Air and water vapor go through the film of the patch. Liquid, water, bacteria, drugs, and other contaminants cannot enter the patch from the outside.
How It Works
The PharmChek® Sweat Patch does not deliver any medications or chemicals to the body, it simply traps the drug metabolite and the parent drug molecules in the absorbent pad for analysis at the laboratory.
PharmChek® tests for cocaine, opiates of codeine, morphine and heroin, amphetamine, methamphetamine, PCP and marijuana. The Sweat Patch detects not only the drug metabolite but also the parent drug.
PharmChek® provides 24/7 continuous monitoring and retains drugs used during the wear period. It is designed for long-term wear and cannot be removed, tampered, or adulterated without detection.
The application and removal procedures are simple and can be done without special facilities.
Store PharmChek® Sweat Patches at room temperature and avoid excessive heat, excessive humidity, or excessive cold.
The PharmChek® Sweat Patch is designed to be worn a minimum of 24 hours, which ensures enough sweat is absorbed into the pad to be tested at the laboratory.
The maximum wear time for the patch is 7 to 10 days, or up to 14 days for some clients with the use of our optional overlay.
The client can perform normal activities such as bathing, showering, participation in sports, or swimming. The PharmChek® Sweat Patch should receive the same degree of care that one would take with a conventional bandage. When drying after a shower or bath, blot the patch, do not rub the towel over it.
The PharmChek® Sweat Patch Application Module will cover:
Several transport bags can go into one mailing envelope. Ship the envelope to:
Clinical Reference Laboratory, Inc.
PO Box 218991
Kansas City, MO 64121-7263
Once the absorbent pad reaches the laboratory, it will have a screening test performed. If the screening test results in a presumptive positive, a confirmation test, using Liquid Chromatography Tandem Mass Spectrometry (LC/MS/MS) will be performed. Results are then certified through a quality assurance review process before being reported out.
SCREENING: The drugs in the pad are extracted into a combination aqueous/organic liquid. An automated pipetting platform pipettes the sample onto a 96-well analytical plate with similarly pipetted calibrators and controls. Following completion of the testing, the data is reviewed by the bench technologist for acceptability, the positive samples are identified, and forwarded to the certification group. If all tests are negative, the certifying official will release the test results to the client. If the sample tests positive for one or more drugs, the sample is transferred to the confirmation laboratory for a LC/MS/MS test.
CONFIRMATION: A laboratory extractionist processes the sample for LC/MS/MS through a series of steps to identify the drug of interest before analysis. The LC/MS/MS generates a printout for data review of every calibrator, control, or sample tested. A review is performed at the bench level for acceptance before sending the data to the certification department.
CERTIFICATION: The certifying scientist reviews the screening and confirmation testing results prior to their release and a quality assurance review of the final test result is performed. If any discrepancy is noted, the sample will be sent back for retesting.