Delayed release peppermint oil capsules (Colpermin) for the spastic colon syndrome: a pharmacokinetic study

Br J Clin Pharmacol. 1984 Oct;18(4):638-40. doi: 10.1111/j.1365-2125.1984.tb02519.x.


Excretion of menthol (as glucuronide) from orally ingested peppermint oil contained in Colpermin was compared with oil contained in two soft gelatine capsules. Total 24 h urinary excretion of menthol was similar in the two formulations in healthy volunteers, but peak menthol excretion levels were lower and excretion delayed with Colpermin. Menthol excretion was reduced in ileostomy patients who took Colpermin and moderate amounts of unmetabolised menthol were recovered from the ileostomy effluent. This is consistent with Colpermin being a delayed-release form of peppermint oil.

MeSH terms

  • Adolescent
  • Adult
  • Capsules
  • Colonic Diseases, Functional / drug therapy*
  • Delayed-Action Preparations
  • Female
  • Humans
  • Ileostomy
  • Kinetics
  • Male
  • Menthol / metabolism
  • Middle Aged
  • Oils, Volatile / administration & dosage
  • Oils, Volatile / metabolism*
  • Plant Extracts / administration & dosage
  • Plant Extracts / metabolism*
  • Plant Oils*


  • Capsules
  • Delayed-Action Preparations
  • Oils, Volatile
  • Plant Extracts
  • Plant Oils
  • Menthol
  • peppermint oil