Hi, I am doing a PBPK simulation to see portal and plasma conc. I am facing problem in poting Dose point/GI equation. Equation are written below; Kindly let me know about GI equation and initial condition for GI Init GI=0 Init Portal=0 Init Liver=0 Init Plasma=0 d/dt(GI)= -DnmolekaFaFg d/dt(Portal) = (QpPlasma+DnmolekaFaFgexp(-katime)-QpPortal)/Vp d/dt(Liver) = ( QaPlasma + QpPortal-Qh*(Liver/Kp)-CLh*(Liver/Kp))/Vl d/dt(Plasma) = (Qh*(Liver/Kp)-QhPlasma-CLnhPlasma)/Vc Qh=(5560)/1000 Qp=(32.960)/1000 Qa=Qh-Qp CLnh=(560)/1000 CLh=(4560)/1000 Vc=31/1000 Vl=78/1000 Vp=8/1000 ka=1.5 FaFg=0.9 Kp=1 Dose=5 Dnmole=Dose*1000000/MWt MWt=500 [file name=gi_portal_liver_plasma.xls size=11264]Certara | Drug Development Solutions (11 KB)
Dear Raj Can you please share your phoenix current code and I can then debug. The equations you wrote are not phoenix based. I am not sure I understand your initial conditions. Is the dosepoint in the GI compartment? Your code even without data will help me identifying the potential problems. Best Regards; Serfge
Hi Dr Serge, This is phoenix converted code. test(){ deriv(GI = -DnmolekaFaFg) deriv(Portal = QpPlasma+DnmolekaFaFgexp(-kat)-QpPortal/Vp) deriv(Liver = QaPlasma + QpPortal-Qh*(Liver/Kp)-CLh*(Liver/Kp)/Vl) deriv(Plasma = Qh*(Liver/Kp)-QhPlasma-CLnhPlasma/Vc) dosepoint(GI) C1=Dnmole error(C1Eps = 1) observe(C1Obs = C1 + C1Eps) C2=Portal error(C2Eps = 1) observe(C2Obs = C2 + C2Eps) C3=Liver error(C3Eps = 1) observe(C3Obs = C3 + C3Eps) C4=Plasma error(C4Eps = 1) observe(C4Obs = C4 + C4Eps) Dnmole=10000 Qh=3.3 Qp=1.974 Qa=Qh-Qp CLnh=0 Vp=0.008 Vl=0.078 Vc=0.031 FaFg=0.9 stparm(ka = (tvka)) stparm(Kp = (tvKp)) stparm(CLh = (tvCLh)) fixef(tvka = c(, 1.5, )) fixef(tvKp = c(, 1, )) fixef(tvCLh = c(, 2.7, )) } Dose input in GI and ut absobed as DosekaFaFgexp(-kat) in portal and goes in liver and systemic ie plasma again coming from plasma to potal My question about is how to put dose point in GI compartment… and get the accurate plasma and portal profile Thanks Raj
Dear Raj You had Dnmole used before being defined. I changed the code and added a random effect to enable simulation using the population interface. It is attached. I hope it helps. best Serge [file name=raj_phsio_OFFICIAL.phxproj size=694863]Certara | Drug Development Solutions (679 KB)
Hi Dr Serge, I am unable to open the file, Could you pls send me the code in text form. Thanks Raj
Here we go test(){ deriv(GI = -DnmolekaFaFg) deriv(Portal = QpPlasma+DnmolekaFaFgexp(-kat)-QpPortal/Vp) deriv(Liver = QaPlasma + QpPortal-Qh*(Liver/Kp)-CLh*(Liver/Kp)/Vl) deriv(Plasma = Qh*(Liver/Kp)-QhPlasma-CLnhPlasma/Vc) dosepoint(GI) Dnmole=10000 C1=Dnmole error(C1Eps = 1) observe(C1Obs = C1 + C1Eps) C2=Portal error(C2Eps = 1) observe(C2Obs = C2 + C2Eps) C3=Liver error(C3Eps = 1) observe(C3Obs = C3 + C3Eps) C4=Plasma error(C4Eps = 1) observe(C4Obs = C4 + C4Eps) Qh=3.3 Qp=1.974 Qa=Qh-Qp CLnh=0 Vp=0.008 Vl=0.078 Vc=0.031 FaFg=0.9 stparm(ka = (tvka*exp(nka))) stparm(Kp = (tvKp)) stparm(CLh = (tvCLh)) fixef(tvka = c(, 1.5, )) fixef(tvKp = c(, 1, )) fixef(tvCLh = c(, 2.7, )) ranef(diag(nka)=c(0.0001)) } [color=#FF4000] One other comment Raj, we are constantly improving the visual debugger as you can see in this screenshot from the 6.4 pre-release. Simon[/color] 
