********** MODEL NAME
model_1cpt_cl_time_dependent
********** MODEL NOTES

PK model for simulation of drug concentration in central compartment
with following characteristics:
Compartments:  1
Elimination :  time dependent clearance
Absorption  :  none (infusion/iv)

Unit convention
Dose: mg
Concentration: ug/mL
Time: hours

The annotation of the parameter units is consistent with the given unit convention.
Units of the inputs (dose) and outputs (concentration) in the dataset for parameter estimation need to match the unit convention.

********** MODEL STATES
d/dt(Ac) 	=  - CL/Vc*Ac + INPUT1
Ac(0)    	= 0

********** MODEL PARAMETERS

CLbase   		  = 3 	# Clearance baseline (L/hour)
CLmax 			  = 10 	# Maximum clearance (L/hour)
Vc 			  = 30 	# Central volume (L)
KI                        = 0.05   # First-order rate constant describing the rate of induction (1/h)
TIlag                     = 5   # Lag time for beginning induction (h)

********** MODEL VARIABLES
% Calculation of concentration in central compartment
Cc 			  = Ac/Vc
% Time dependent CL
CL = CLmax-(CLmax-CLbase*exp(-(time-TIlag)*KI))

% Defining an output (only needed when interfacing with NLME
% parameter estimation tools such as NONMEM and MONOLIX)
OUTPUT1  	  = Cc  # Compound concentration (ug/mL)

********** MODEL REACTIONS


********** MODEL FUNCTIONS


********** MODEL EVENTS