PHAR 4634 - Chapter 5 Page 6

Plot Types

Cumulative amount excreted versus time

(Equation V-8)

Figure V-4. Linear Plot of U versus Time showing Approach to U not equal to DOSE

Using a JAVA aware browser you can create your own version of Figure V-4.

Cumulative Amounts Excreted as Unchanged Drug into Urine Plots

Rate of excretion (R/E)

Equation V-15. Natural log of Rate of Excretion versus Time

Note: ke * DOSE not kel * DOSE

Figure V-5. Semi-log Plot of U/t versus Time_midpoint Showing Slope = - kel

with fe = 0.75, kel = 0.2 hr^-1; ke = 0.15 hr^-1

Using a JAVA aware browser you can create your own version of Figure V-5.

Rate of Excretion as Unchanged Drug into Urine Plots

Amount remaining to be excreted (A.R.E.)

(Equation V-8)

= U - U * e^{- kel * t}

(U - U) = U * e^{- kel * t}

then ln (U - U) = ln U- kel * t

Note ke

Thus,

Figure V-6. Semi-Log Plot of A.R.E. versus Time

Using a JAVA aware browser you can create your own version of Figure V-6.

Amount Remaining to be Excreted as Unchanged Drug into Urine Plots

For practice you can use these urine data collected after an IV bolus dose and estimate pharmacokinetic parameters. Compare your answers with the computer!

This page was last modified: 3 May 2002