Our In Vitro Drug Metabolism Group has extensive knowledge and offers a wide range of In Vitro studies in microsomes, S9 fractions, and hepatocytes.
Our In Vitro Study services include:
- Interspecies Profiling
- Inhibition
- Induction
- Isozyme Characterization
- Drug-Drug Interactions
- Metabolic Stability
All of our studies are supported by conventional and mass spectrometry technologies.
Interspecies Profiling
We provide comparative metabolite profiling to assist you in the selection of the most appropriate toxicology species. We can also provide additional metabolite identification by LC-MS/MS to provide structural elucidation of observed metabolites.
Our team is capable of assessing integrated Phase I and Phase II metabolism.
We have bioanalytical capabilities to investigate both radiolabeled and non-radiolabeled drugs.
Inhibition
Inhibition of cytochrome P450 enzymes (CYP1A2, 2A6, 2C8, 2C9, 2C19, 2D6, 2E1 & 3A) by candidate drugs, including investigations of:
Direct Inhibition (IC50 and Ki)
Chart Details: Determination of IC50 for ketoconazole (10 µM to 0.001 µM) against CYP3A activity at 5 µM midazolam: Variability between 2 different pools of human liver microsomes
Mechanism Based Inhibition (preliminary investigation, KI and Kinact)
Chart Details: Determination of Kinact and KI for furafylline against CYP1A2 (phenacetin O-deethylase) activity (Y axis label: ln % residual activity)
Induction
We can conduct studies using human hepatocytes with estimation of cytochrome P450 CYP1A2, 2C9 & 3A enzymes activities. Hepatocytes are exposed for 72 hours to the test compound at three different concentrations and to model inducers. Control hepatocytes are included and exposed to the test compound vehicle.
We can estimate the induction of cytochrome P450 CYP1A, 2B, 2E, 3A and 4A enzyme activities through induction on ex vivo livers from toxicology studies. We can also source livers through our in-house animal dosing activities.
We can establish total protein and cytochrome P450 content. We monitor for LDH leakage and signs of cytotoxicity.
Isozyme Characterisation
Our team can identify the cytochrome P450 isoenzymes involved in the metabolism of test substances.
We offer a combined approach utilizing:
- Chemical inhibitors
- SupersomesTM
- Lymphoblastoid cells
- Cytochrome P450 antibodies
- Correlation analysis
Cytochrome P450 Identification
Drug-Drug Interactions
Method development can be carried out to establish methods to assess the interaction of test substances on metabolism of potentially co-administered drugs and assess the affect of co-administered drugs on the metabolism of test substances.
Our study designs can also include evaluation of:
- IC50 and Ki
- Species variation in metabolism [hepatic and extrahepatic whole cells (e.g. hepatocytes) and subcellular fractions (e.g. microsomes)]
- Drug-drug interactions (CYP450 inhibition and induction)
- Protein binding (equilibrium dialysis or ultrafiltration as well as high throughput HSA and AGP assay)
Metabolic Stability
We conduct In Vitro metabolic stability using liver S9 fraction, microsomes and hepatocytes in single or multiple species. We can supply estimation of half-life (t
1/2), intrinsic clearance (CL
int) and hepatic clearance (CL
h). Further analysis of incubations by LC-MS/MS can also be undertaken to provide structural elucidation of observed metabolites.