The use of BDDCS in classifying the permeability of marketed drugs

Pharm Res. 2008 Mar;25(3):483-8. doi: 10.1007/s11095-007-9523-x. Epub 2008 Jan 31.


We recommend that regulatory agencies add the extent of drug metabolism (i.e., >or=90% metabolized) as an alternate method in defining Class 1 marketed drugs suitable for a waiver of in vivo studies of bioequivalence. That is, >or=90% metabolized is an additional methodology that may be substituted for >or=90% absorbed. We propose that the following criteria be used to define>or=90% metabolized for marketed drugs: Following a single oral dose to humans, administered at the highest dose strength, mass balance of the Phase 1 oxidative and Phase 2 conjugative drug metabolites in the urine and feces, measured either as unlabeled, radioactive labeled or nonradioactive labeled substances, account for >or=90% of the drug dosed. This is the strictest definition for a waiver based on metabolism. For an orally administered drug to be >or=90% metabolized by Phase 1 oxidative and Phase 2 conjugative processes, it is obvious that the drug must be absorbed. This proposal, which strictly conforms to the present>or=90% criteria, is a suggested modification to facilitate a number of marketed drugs being appropriately assigned to Class 1.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Administration, Oral
  • Drug Approval
  • Humans
  • Intestinal Absorption*
  • Jejunum / metabolism*
  • Metabolic Detoxication, Phase I
  • Metabolic Detoxication, Phase II
  • Permeability
  • Pharmaceutical Preparations / administration & dosage
  • Pharmaceutical Preparations / classification*
  • Pharmaceutical Preparations / metabolism
  • Pharmacokinetics*
  • Solubility
  • Therapeutic Equivalency


  • Pharmaceutical Preparations