Introduction To Pharmacokinetics
Method Of Residuals
RESIDUALS GRAPH - FIRST ORDER PROCESS
If the residuals graph is a straight line, this tells you that the absorption process follows first order kinetics: a constant proportion of drug is absorbed and the amount of drug absorbed is dependent on the concentration.
When there is first order kinetics, you can go on and use the residuals graph to find the absorption half-life and from that, the absorption rate constant.
Looking at the residuals graph just obtained, you can see that the residuals graph IS a straight line. The absorption process follows first order kinetics.
You can therefore use the residuals graph to find the absorption half-life.
(This is illustrated on the next page.)
