Food increases the bioavailability of isotretinoin

J Clin Pharmacol. Nov-Dec 1983;23(11-12):534-9. doi: 10.1002/j.1552-4604.1983.tb01800.x.


Twenty healthy male subjects received 80 mg (2 X 40 mg SEG capsules) oral isotretinoin separated by two-week washout periods in an open randomized crossover design. Isotretinoin was administered during a complete fast, 1 hour after a standard breakfast, with a standard breakfast, or 1 hour before a standard breakfast. Blood samples were obtained at specific times over a 72-hour period. Isotretinoin blood concentrations were determined by a specific HPLC method. The relative bioavailability (AUC) of isotretinoin was found to be approximately 1.5 to 2 times greater when the dose was administered 1 hour before, concomitantly with, or 1 hour after a meal than when it was given during a complete fast. In addition, because the Cmax value is lower when the dose is administered with food rather than 1 hour after a meal, coadministration of isotretinoin with food may be the best method of administration.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Analysis of Variance
  • Biological Availability
  • Eating*
  • Fasting
  • Humans
  • Isotretinoin
  • Male
  • Tretinoin / blood
  • Tretinoin / metabolism*


  • Tretinoin
  • Isotretinoin