Can anybody help me in writing the code using phoenix for the picture depicted in the attachment.
The explanation for the picture is the drug is present in the plasma (tissue chamber in this case) and the free drug passes through the membrane in to the buffer chamber.
There can be elimination from both chambers due to instability of the compound (indicated as KelT and KelB from tissue and buffer chambers respectively).
KonDP and Koff DP indicate association and dissociation of drug protein complex.
The processes you describe are not first order but second order at least. Therefore you cannot define the model graphically. You need to write down the differential equations using the pml language.
Please write the equations and I can help you with the code. If you have trouble writing the equaitons, let me know but define the processes that occur and the assumptions if any you are making.
Tissue Compartment
dDtissue/ dt = PSA/V × (Dbuffer − Dtissue) − Dtissue(kon,DP×Ptissue ) + koff ,DP × DPtissue − Dtissue × kel,T
dDPtissue / dt = kon,DP × Dtissue × Ptissue − koff ,DP × DPtissue
dPtissue / dt = koff ,DP × DPtissue − kon,DP × Dtissue × Ptissue
Buffer Compartment (Receiver)
dDbuffer / dt = PSA /V x (Dtissue − Dbuffer) − Dbuffer × kel,B
The following are the definitions of the terms used:
Dtissue: Drug present in the tissue compartment or chamber
PSA: polar surface area and is a constant
Dbuffer: drug present in buffer chamber
Kon,DP : Formation rate constant of Drug + protein complex
Koff,DP : dissociation rate constant of Drug + protein complex
DPtissue : Drug protein complex in the tissue chamber
Ptissue: Protein present in the tissue compartment
kel,T: Elimination of drug from the tissue compartment due to instability
kel,B: elimination of drug from the buffer compartment due to instability
V is the volume of the chamber