Re:Re: simluation Tmax Cmax AUC

Dear Sebastien:I have to say that my admiration to you is beyond the words,because you have directly pointed out the radical essence.Could the ke or the V/F,any one , be derived from the known Cmax,AUC,?As far as I have leaned ,the equations are as follows: AUC=Dose*F/Ke*V,Cmax=(F*Dose/V)*(exp(Ka*Tmax)-epx(Ke*Tmax)).After the computation and transformation ,I was obstructed in the front of the following: Ke-2.1*Ln(Ke)=3.18.something like that, well I could not remember the constant number (2.1 e.g.) clearly. I am not able to solve that equation.So,I decide to make some equations in the $PK,in which the CL V and Ka could all be expressed as the component of Tmax ,Cmax,and AUC at the same time.The suggestion you have made is usefull,but still a little problem :the Ke.Thank you for your generous help.22 03:24:55，"Sebastien Bihorel" <[email protected]>Hi, > >It looks like you are trying to derive the unknown values of KA, CL/F >and V/F from the known values of Tmax, Cmax and AUC (probably obtained >from a non compartmental analysis). > >If that is really the case, you will need to know the values of the >half-life of elimination or the slope of elimination Ke to solve for Ka >and V/F (the following solutions assume a one-compartment model with >linear absorption and elimination): > >CL/F = Dose/AUC > >V/F = (CL/F)/Ke > >KA = - (1/tmax)*ln[ exp(-ke*tmax) - (Cmax*V)/(F*dose) ] > >If you don't know Ke, you will have to solve for V/F and Ka numerically, >prior to your simulation. > >Sebastien > >yhb5442387 wrote: >> >> Dear Nmuser: >> >> I would like to do a data simulation .The distributions of the drug >> population pharmaockinetics were assumed to be normal.But the profile >> that I have got is Tmax, Cmax,and AUC(the means and variances are >> already known),instead of Ka,CL,and V. What the $PK modification >> should I have to do in the model where the advan2 has been taken in >> the $subroutine. >> >> F=1. >> >> Any suggestion would be appreciated. >> >> Yours,ye hong bo >> >> >> >> >> -- >> 工作和生活,都要开心的过. >> 你好,叶红波在此送上真挚的祝福.祝你开心, >> 叶红波 >> >> -- 工作和生活,都要开心的过. 你好,叶红波在此送上真挚的祝福.祝你开心, 叶红波