10 Formulas workshop Flashcards
1
Q
pH
A
pH = pKa + log(A-/HA)
2
Q
% drug protonated or unprotonated
A
log(HA/A-) = pKa - pH = log(protonated/unprotonated)
ie. protonated/(protonated+unprotonated) = %protonated
3
Q
F(bioavailability)
A
F (bioavailability) = [Plasma Conc]new route/[Plasma Conc]old route
4
Q
Dose for New Route
A
Dose for New Route = ([Dose]old route x Fold route)/[F]new route
5
Q
Vd
A
Vd = Dose / [Plasma]Drug
6
Q
K (rate of elimination)
A
K=CL x P(lasma conc)
7
Q
t_1/2 (half life)
A
t_1/2=[0.7 x Vd]/CL
8
Q
therapeutic index
A
TI = TD50 / ED50
9
Q
Loading Dose
A
Loading Dose = Target dose conc x Vd
10
Q
Maintenance Dose
A
Maintenance Dose = CL/F = (CL x Target dose conc)/dosing interval
