Usefulness of sweat testing for the detection of methylphenidate after fast- and extended-release drug administration: a pilot study

Ther Drug Monit. 2010 Aug;32(4):508-11. doi: 10.1097/FTD.0b013e3181e4e6f8.


The pharmacokinetics of methylphenidate (MPH), a prescription amphetamine derivative used in the treatment of attention-deficit hyperactivity disorder, has been amply described in conventional biological matrices. Recently, the excretion of MPH and its principal metabolite, ritalinic acid (RA) in oral fluid and plasma after a single drug administration has been described. The aim of this study was to describe the excretion of MPH and RA in sweat after the administration of a single dose of either fast-release or extended-release MPH. Three male subjects received 2 simultaneous oral doses of 10 mg fast-release MPH, and 1 male subject received one dose of 20 mg extended-release MPH. Sweat patches were applied to the back of each participant and removed at timed intervals. MPH and RA were determined in patches using a previously validated liquid chromatography-electrospray ionization mass spectrometric method. MPH was detected in sweat after the administration of fast- and extended-release formulations. For the fast-release formulation, MPH appeared in the sweat patches 2 hours after administration with a maximum of 15.9 nanogram per patch, reached after 24 hours. Mean total MPH excreted was 0.02 mg (about 0.08% of the administered dose). For the extended-release formulation, MPH appeared in the sweat 5 hours after administration and reached a maximum of 34.3 nanogram per patch after 24 hours. Mean total MPH excreted was 0.04 mg (about 0.18% of the administered dose). RA was not detected in either of the sweat patches probably because of its acidic properties. Measuring MPH in sweat patches can be a viable alternative to urine testing for noninvasive monitoring of use and misuse of the drug.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Central Nervous System Stimulants / administration & dosage
  • Central Nervous System Stimulants / analysis*
  • Central Nervous System Stimulants / pharmacokinetics
  • Delayed-Action Preparations
  • Dose-Response Relationship, Drug
  • Humans
  • Male
  • Methylphenidate / administration & dosage
  • Methylphenidate / analogs & derivatives
  • Methylphenidate / analysis*
  • Methylphenidate / pharmacokinetics
  • Pilot Projects
  • Substance Abuse Detection / methods*
  • Sweat / chemistry*
  • Young Adult


  • Central Nervous System Stimulants
  • Delayed-Action Preparations
  • Methylphenidate
  • ritalinic acid