Figure 3-20 The disposition of a three-compartment model (i.e., triexponential model) consists of the sum of three monoexponential functions. The concentrations over time are the algebraic sum of three separate functions, Ae^-αt , Be^-βt , and Ce^-γt . Typically, α > β > γ by about one order of magnitude. The functions can be graphed separately (solid lines) and as their sum (dotted line).