One example of a PBPK model
Organ/Tissue |
Blood flow, Q (mL/min) |
Organ Volume, V (mL) |
Tissue/Blood Partition Coefficient, R |
Clearance, CL (mL/min) |
---|---|---|---|---|
Venous | 2,700 | 800 | 1.0 | |
Arterial | 2,700 | 1,600 | 1.0 | |
Lung | 2,700 | 375 | 0.9 | |
Liver | 460 | 790 | 0.9 | 76.8 |
Spleen | 75 | 60 | 0.9 | |
Kidney | 330 | 165 | 0.9 | 61.8 |
Heart | 97 | 200 | 0.9 | |
Muscle | 280 | 18,300 | 0.9 | |
Other | 1,458 | 11,710 | 1.0 | |
Total | 2,700 | 34,000 |
One example of a PBPK model with the Components Numbered
Data sets are numbered as well. We can use the same number as for the components except that we may not have data for Arterial blood or Other. Another data set might be drug in urine following clearance from the Kidney.
>cd /Directory/For/This/Analysis >boomer Boomer v3.4.5 Ref: Comput.Meth.Prog.Biomed.,29 (1989) 191-195 David W.A. Bourne Copyright 1986-2018 D.W.A. Bourne See http://www.boomer.org or email david@boomer.org for more info Based on the original MULTI by K. Yamaoka, et.al. J. Pharmacobio-Dyn., 4,879 (1981); ibid, 6,595 (1983); ibid, 8,246 (1985) DATA ENTRY 0) From KEYBOARD 1) From .BAT file -1) From .BAT file (with restart) 2) From KEYBOARD creating .BAT file 3) From .BAT file (quiet mode) -3) From .BAT file (quiet mode-with restart) 4) to enter data only 5) to calculate AUC from a .DAT file -9) to quit -8) Registration Information Enter choice (0-5, -1, -3, -8 or -9) 2 Enter .BAT filename pbpk_sim The output .BAT filename is pbpk_sim.BAT METHOD OF ANALYSIS 0) Normal fitting 1) Bayesian 2) Simulation only 3) Iterative Reweighted Least Squares 4) Simulation with random error or sensitivity analysis 5) Grid Search -5) To perform Monte Carlo run (Only once at the start of BAT file) -4) To perform multi-run (End of BAT file only) -3) To run random number test subroutine -2) To close (or open) .BAT file -1) To finish Enter choice (-3 to 5) 2 Where do you want the output? 0) Terminal screen 1) Disk file Enter choice (0-2) 1 Enter .OUT filename pbpk_sim The output .OUT filename is pbpk_sim.OUT
Enter the parameters for this run. Note parameters 15-17 for PBPK models.
Parameters currently available in Boomer for model building
Enter the Dose - here a bolus 100 mg dose into the Venous component (1).
Enter type# for parameter 1 (-5 to 51) 1 Enter Dose value 100.0 Enter component to receive dose 1 Enter component for F-dependence ( 1 to - 1 or 0 for no dependence) 0 Input summary for Dose (type 1) Fixed value is 100.0 Dose/initial amount added to 1 Enter 0 if happy with input, 1 if not, 2 to start over 0
Enter parameters for the Vein to Lung step and output to the first data set, Venous (1). Note that the value for R(Vein) is 1. The first data set is for Vein.
Enter type# for parameter 2 (-5 to 51) 15 Enter parameter name Vein > Lung Enter Q Vein > Lung value 2700. Enter component to receive flux 3 Enter component to lose flux 1 Input summary for Q Vein > Lung (type 15) Fixed value is 2700. Transfer from 1 to 3 Enter 0 if happy with input, 1 if not, 2 to start over 0 Enter V Vein > Lung value 800.0 Enter data set (line) number 1 Enter line description [Vein] Input summary for V Vein > Lung (type 16) Fixed value is 800.0 Component 1 added to line 1 Enter 0 if happy with input, 1 if not, 2 to start over 0 Enter R Vein > Lung value 1.000 Input summary for R Vein > Lung (type 17) Fixed value is 1.000 Enter 0 if happy with input, 1 if not, 2 to start over 0
The next step is from Lung to Artery. Here we enter the volume and partition coefficient for the Liver. For organs other than Vein, Artery and Other we will assume R is 0.9. The second data set is Lung.
Enter type# for parameter 5 (-5 to 51) 15 Enter parameter name Lung > Artery Enter Q Lung > Artery value 2700. Enter component to receive flux 2 Enter component to lose flux 3 Input summary for Q Lung > Artery (type 15) Fixed value is 2700. Transfer from 3 to 2 Enter 0 if happy with input, 1 if not, 2 to start over 0 Enter V Lung > Artery value 375.0 Enter data set (line) number 2 Enter line description [Lung] Input summary for V Lung > Artery (type 16) Fixed value is 375.0 Component 3 added to line 2 Enter 0 if happy with input, 1 if not, 2 to start over 0 Enter R Lung > Artery value 0.9000 Input summary for R Lung > Artery (type 17) Fixed value is 0.9000 Enter 0 if happy with input, 1 if not, 2 to start over 0
Now we can start on the output from the Artery with Liver.
Enter type# for parameter 8 (-5 to 51) 15 Enter parameter name Artery > Liver Enter Q Artery > Liver value 460.0 Enter component to receive flux 4 Enter component to lose flux 2 Input summary for Q Artery > Liver (type 15) Fixed value is 460.0 Transfer from 2 to 4 Enter 0 if happy with input, 1 if not, 2 to start over 0 Enter V Artery > Liver value 1600. Enter data set (line) number 3 Enter line description [Artery] Input summary for V Artery > Liver (type 16) Fixed value is 1600. Component 2 added to line 3 Enter 0 if happy with input, 1 if not, 2 to start over 0 Enter R Artery > Liver value 1.000 Input summary for R Artery > Liver (type 17) Fixed value is 1.000 Enter 0 if happy with input, 1 if not, 2 to start over 0
We have already entered V and R values for Artery so they don't need to added for the next entry for Spleen, just the Q value.
Enter type# for parameter 11 (-5 to 51) 15 Enter parameter name Artery > Spleen Enter Q Artery > Spleen value 75.00 Enter component to receive flux 5 Enter component to lose flux 2 Input summary for Q Artery > Spleen (type 15) Fixed value is 75.00 Transfer from 2 to 5
Next we can enter the parameters for Spleen to Liver
Enter type# for parameter 14 (-5 to 51) 15 Enter parameter name Spleen > Liver Enter Q Spleen > Liver value 75.00 Enter component to receive flux 4 Enter component to lose flux 5 Input summary for Q Spleen > Liver (type 15) Fixed value is 75.00 Transfer from 5 to 4 Enter 0 if happy with input, 1 if not, 2 to start over 0 Enter V Spleen > Liver value 60.00 Enter data set (line) number 4 Enter line description [Spleen] Input summary for V Spleen > Liver (type 16) Fixed value is 60.00 Component 5 added to line 4 Enter 0 if happy with input, 1 if not, 2 to start over 0 Enter R Spleen > Liver value 0.9000 Input summary for R Spleen > Liver (type 17) Fixed value is 0.9000
Parameters, i.e Q values, for the rest of the transfer from Artery to Kidney, Heart, Muscle and Other follow in the same way. Next we start to add the transfer from Liver through Other to Vein starting with Liver. We enter Liver blood flow, volume and partition coefficient value.
Enter type# for parameter 29 (-5 to 51) 15 Enter parameter name Liver > Vein Enter Q Liver > Vein value 535.0 Enter component to receive flux 1 Enter component to lose flux 4 Input summary for Q Liver > Vein (type 15) Fixed value is 535.0 Transfer from 4 to 1 Enter 0 if happy with input, 1 if not, 2 to start over 0 Enter V Liver > Vein value 790.0 Enter data set (line) number 5 Enter line description [Liver] Input summary for V Liver > Vein (type 16) Fixed value is 790.0 Component 4 added to line 5 Enter 0 if happy with input, 1 if not, 2 to start over 0 Enter R Liver > Vein value 0.9000 Input summary for R Liver > Vein (type 17) Fixed value is 0.9000
The rest of the tissue to Vein transfer are entered in the same way. A link to the complete BAT and OUT files is provided below. The last step in this model is to include an elimination (or clearance) step. Here we have elimination from the Vein but it could be from Liver and/or Kidney. Elimination is to outside the model, 0, but it could be to a Urine or Metabolite component.
Enter type# for parameter 44 (-5 to 51) 2 Enter parameter name Elimination Enter Elimination value 1.500 Enter component to receive flux 0 Enter component to lose flux 1 Input summary for Elimination (type 2) Fixed value is 1.500 Transfer from 1 to 0
With all this data entered Boomer will provide a Flow balance table. The in and out values should be the same or the plumbing is wrong.
Flow balance for Physiological Model Component 1) in 2700. out 2700. Component 2) in 2700. out 2700. Component 3) in 2700. out 2700. Component 4) in 460.0 out 460.0 Component 5) in 75.00 out 75.00 Component 6) in 330.0 out 330.0 Component 7) in 97.00 out 97.00 Component 8) in 280.0 out 280.0 Component 9) in 1458. out 1458.
Next the numerical integration method is chosen and a description entered before entering the data. PBPK systems are typical 'stiff' (very slow and very fast transfers) so Gears method is a good choice.
Method of Numerical Integration 0) Classical 4th order Runge-Kutta 1) Runge-Kutta-Gill 2) Fehlberg RKF45 3) Adams Predictor-Corrector with DIFSUB 4) Gears method for stiff equations with PEDERV 5) Gears method without PEDERV Enter choice (0-5) 4 Enter Absolute error term for Numerical integration (0.001) 0.000 Enter description for this analysis: Simulation of PBPK Model Enter data from 0) Disk file 1) Keyboard Enter Choice (0-1) 1 Enter data for [Vein] Enter x-value (time) = -1 to finish data entry X-value (time) 0.000 Y-value (concentration) 0.000
After entering values for each data set exit by entering -1 for X-value. For these simulations Y-values can be entered as 0. Check for errors, save or not and move to the next data set. After all the data sets are entered you can choose to calculate a AUC values or other options such as graphs.
X-value (time) 24.00 Y-value (concentration) 0.000 X-value (time) -1.000 Data for [Artery] DATA # Time Concentration 1 0.000 0.000 2 1.000 0.000 3 2.000 0.000 4 3.000 0.000 5 4.000 0.000 6 5.000 0.000 7 6.000 0.000 8 8.000 0.000 9 12.00 0.000 10 14.00 0.000 11 16.00 0.000 12 18.00 0.000 13 21.00 0.000 14 24.00 0.000 Do you want to 0) Accept data 1) Correct data point 2) Delete data point 3) Insert new data point 4) Add offset to x-value Enter choice (0-3) 0 Save Observed Data to Disk Module 0) Continue without saving 1) Save data for [Artery on disk Enter choice 0 Calculation of AUC and AUMC section 0) Exit this section 1) [Vein] 2) [Lung] 3) [Artery] 4) [Spleen] 5) [Liver] 6) [Kideny] 7) [Heart] 8) [Muscle] 9) [Other] Enter line # for required AUC (0- 9) 0 Additional Output Enter -> 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Save Data x x x x x x x x Graphs x x x x x x x x Extra files x x x x x x x x Sensitivity x x x x x x x x Save calculated data files, Produce linear, semi-log and weighted residual plots, save extra data files or perform sensitivity or optimal sampling analysis Enter choice (0-15) 2
Among other output information Boomer provides a summary of the model as entered. Here we can check for errors. The BAT file can be edited and re-run as needed. The flow balance is output as well as the calculated data.
Model and Parameter Definition # Name Value Type From To Dep Start Stop 1) Dose = 100.0 1 0 1 0 0 0 2) Q Vein > Lung = 2700. 15 1 3 0 0 0 3) V Vein > Lung = 800.0 16 1 1 0 0 0 4) R Vein > Lung = 1.000 17 0 0 0 0 0 5) Q Lung > Artery = 2700. 15 3 2 0 0 0 6) V Lung > Artery = 375.0 16 3 2 0 0 0 7) R Lung > Artery = 0.9000 17 0 0 0 0 0 8) Q Artery > Liver = 460.0 15 2 4 0 0 0 9) V Artery > Liver = 1600. 16 2 3 0 0 0 10) R Artery > Liver = 1.000 17 0 0 0 0 0 11) Q Artery > Spleen = 75.00 15 2 5 0 0 0 12) V Artery > Spleen = 1600. 16 2 0 10900 0 0 13) R Artery > Spleen = 1.000 17 0 0 11000 0 0 14) Q Spleen > Liver = 75.00 15 5 4 0 0 0 15) V Spleen > Liver = 60.00 16 5 4 0 0 0 16) R Spleen > Liver = 0.9000 17 0 0 0 0 0 17) Q Artery > Kidney = 330.0 15 2 6 0 0 0 18) V Artery > Kidney = 1600. 16 2 0 10900 0 0 19) R Artery > Kidney = 1.000 17 0 0 11000 0 0 20) Q Artery > Heart = 97.00 15 2 7 0 0 0 21) V Artery > Heart = 1600. 16 2 0 10900 0 0 22) R Artery > Heart = 1.000 17 0 0 11000 0 0 23) Q Artery > Muscle = 280.0 15 2 8 0 0 0 24) V Artery > Muscle = 1600. 16 2 0 10900 0 0 25) R Artery > Muscle = 1.000 17 0 0 11000 0 0 26) Q Artery > Other = 1458. 15 2 9 0 0 0 27) V Artery > Other = 1600. 16 2 0 10900 0 0 28) R Artery > Other = 1.000 17 0 0 11000 0 0 29) Q Liver > Vein = 535.0 15 4 1 0 0 0 30) V Liver > Vein = 790.0 16 4 5 0 0 0 31) R Liver > Vein = 0.9000 17 0 0 0 0 0 32) Q Kidney > Vein = 330.0 15 6 1 0 0 0 33) V Kidney > Vein = 165.0 16 6 6 0 0 0 34) R Kidney > Vein = 0.9000 17 0 0 0 0 0 35) Q Heart > Vein = 97.00 15 7 1 0 0 0 36) V Heart > Vein = 200.0 16 7 7 0 0 0 37) R Heart > Vein = 0.9000 17 0 0 0 0 0 38) Q Muscle > Vein = 280.0 15 8 1 0 0 0 39) V Muscle > Vein = 0.1830E+05 16 8 8 0 0 0 40) R Muscle > Vein = 0.9000 17 0 0 0 0 0 41) Q Other > Vein = 1458. 15 9 1 0 0 0 42) V Other > Vein = 0.1171E+05 16 9 9 0 0 0 43) R Other > Vein = 1.000 17 0 0 0 0 0 44) Elimination = 1.500 2 1 0 0 0 0 Flow balance for Physiological Model Component 1) in 2700. out 2700. Component 2) in 2700. out 2700. Component 3) in 2700. out 2700. Component 4) in 535.0 out 535.0 Component 5) in 75.00 out 75.00 Component 6) in 330.0 out 330.0 Component 7) in 97.00 out 97.00 Component 8) in 280.0 out 280.0 Component 9) in 1458. out 1458. Data for [Vein] :- DATA # Time Observed Calculated (Weight) Weighted residual 1 0.000 0.00000 0.125000 0.00000 -0.00000 2 1.000 0.00000 0.394549E-02 0.00000 -0.00000 3 2.000 0.00000 0.341332E-02 0.00000 -0.00000 4 3.000 0.00000 0.277143E-02 0.00000 -0.00000 5 4.000 0.00000 0.231940E-02 0.00000 -0.00000 6 5.000 0.00000 0.201767E-02 0.00000 -0.00000 7 6.000 0.00000 0.180599E-02 0.00000 -0.00000 8 8.000 0.00000 0.152751E-02 0.00000 -0.00000 9 12.00 0.00000 0.120182E-02 0.00000 -0.00000 10 14.00 0.00000 0.108403E-02 0.00000 -0.00000 11 16.00 0.00000 0.981852E-03 0.00000 -0.00000 12 18.00 0.00000 0.891648E-03 0.00000 -0.00000 13 21.00 0.00000 0.774626E-03 0.00000 -0.00000 14 24.00 0.00000 0.675644E-03 0.00000 -0.00000
Linear and semi-log printer-style plots can be output for a quick review of the results.
Plots of observed (*) and calculated values (+) versus time for [Lung]. Superimposed points (X) 0.4424E-02 Linear 0.4424E-02 Semi-log | + | + | | | | | | | | | | | | + | | | | | + | + | | | | | | + | + | | | + | | + | + | | | | + | + | + | | | | + | | | + | + | + | + + | | + | + | + + | + | | | | + | | |X* ** ** * * * * * * * * | + |_____________________________________ |X*_**_**_*__*_____*__*__*__*___*____* 0.000 0.6115E-03 0 <--> 24. 0 <--> 24.
The complete BAT and OUT files can be dowloaded.
The BAT file can be saved as PBPK.BAT and run with Boomer. With the current version of Boomer for Windows the lineEnter component for F-dependence ( 1 to - 1 or 0 for no dependence) 0
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