
102 Computational Pharmacokinetics
MRT =
k
pc
+ k
pe
+ k
cp
k
ce
(k
pc
+ k
pe
)+k
cp
k
pe
(5.8)
V
ss
= CL
av
· MRT = V
c
(1 +
k
cp
k
pc
+ k
pe
). (5.9)
Another expression for MRT expresses it in the observable version, MRT
app
(see Box 5.1):
MRT = MRT
app
+
k
pe
k
cp
(k
pc
+ k
pe
)(k
ce
(k
pc
+ k
pe
)+k
cp
k
pe
)
, (5.10)
where the correction term is non-zero only if there is some peripheral elimi-
nation. If we have only peripheral elimination the correction term is
1
k
pc
+ k
pe
.
In the distribution process there is a point when the flow into the peripheral
compartment is precisely balanced by what is eliminated from it. Such a point
t
∗
is characterized by
(k
pc
+ k
pe
)M
p
(t
∗
)=k
cp
M
c
(t
∗
)
and at such a point the v