Compartment (pharmacokinetics)

Compartment (pharmacokinetics)

In pharmacokinetics, a compartment is a defined volume of body fluids. It is distinguished from anatomic compartments, which are bounded by fasciae. It is used in multi-compartment models.


There are five major body compartments:[1]

The transcellular compartment includes fluids in the pleural cavity or peritoneal cavity.

Comparison table

Compartment estimated % of body mass[1]
blood plasma 5
interstitial fluid 16
fat tissue 20 (see also body fat percentage)
intracellular fluid 35
transcellular fluid 2

Mnemonic: 60-40-20-15-5: % of TBW, Intracellular fluid, Extracellular fluid, interstitial fluid, plasma


  1. ^ a b Rang, H. P. (2003). Pharmacology. Edinburgh: Churchill Livingstone.   Page 102