TABLE 1.

Model-building steps

Model	No. of parameters	Objective function values
Model 2, one-compartment model with first-order input rate and with a lag time	7	4,534
Model 3, one-compartment model with first-order input rate and without a lag time	6	4,554
Model 4, one-compartment model with zero-order input rate and with absorption duration estimated from the data	6	4,970