PK Hep CL

Assay type hierarchy

1. bioassay
2. ›pharmacokinetic assay
3. ›metabolic stability assay
4. ›hepatocyte stability assay
5. ›clearance assay

Assay type *

clearance assay

Experimental setting *

in vitro

Assay format *

cell-based

Assay design

time-course

Target *

⚠hepatic enzymes

Biological process

drug metabolism

Molecule role *

substrate

Cell system

hepatocytes

Species

Not set

Donor source

Not set

Plating format

Not set

Incubation duration

Not set

Detection type *

UPLC-MS/MS

Physical detection method *

mass spectrometry

Reference gene

Not set

Expected readout *

t1/2CLintFmax

Metabolic stabilities of NCEs in hepatocytes are determined by incubating the compounds at low concentrations (preferably below 1uM) and at low cell numbers (preferably at 1*10^6cells/ml) to ensure linear kinetics as good as possible. 7 timepoints from the incubation mixture are withdrawn for analysis to define the halflife of the compound. From that halflife, different clearance values and an Fmax value are calculated for the compound. The CL and Fmax values reflect Phase I and II metabolism in hepatocytes. To minimize the influence of organic solvents in the incubation mixture their content is limited to max. 1% for ACN or max. 0.2% for DMSO. For all species and strains, the cell number of hepatocytes is supposed to be 1.1*10^8cells/g liver. Those values based on half-lives exceeding incubation times can only be considered as rough estimates! Calculated parameters are: Fmax-wellstirred [%]: maximal bioavailability after peroral administration: (1-CL blood-wellstirred/QH)*100 CL blood-wellstirred [l/(h*kg)]: estimated blood clearance (QH*CL intrinsic) / (QH+CL intrinsic) CL intrinsic [l(h*kg)]: maximum ability of the liver (hepatocytes) to eliminate a compound, if liver blood flow were not limiting (kel*liver weight) / fraction of liver (cell number) in incubation CL intrinsic-apparent [ml/(min*10^6cells)]: reflects the elimination constant kel (min-1) of the cmpd in the incubation mixture divided by the cell number used (x*10^6/ml) t 20min [%]: cmpd [%] left after 20 min t 1/2 [min]: halflife of the cmpd in incubation mixture

• Imported from PK Hep CL.json

  Dr Amelia Ostrowski · 18/08/2026, 19:33:36