Currently available ADMET assays are summarised here and include physicochemical properties, metabolism, and toxicity with more in development (cross-species hepatocyte stability and kinetics).

See the table below for additional details, including average turnaround time. Primary, secondary, and tertiary ADME assays as well as toxicity assays and their general uses are outlined in additional detail for each category below, including average turnaround time. For assays where an average turnaround time/control(s) is not available, this indicates that turnaround time is dependent on your unique experimental design and conditions; please book a consultation for an estimated turnaround time or additional information.

Please note: many ADME assays (absorption, distribution, metabolism, excretion) assays require infusion and solubility analyses.

H3D's expertise and experience is especially pronounced in the following DMPK areas:

The physicochemical properties of a compound strongly influence its biopharmaceutical profile and characteristics. Assays to evaluate and characterize physicochemical properties of a compound analyze a drug or candidate compounds journey through the body and include multiple different phases. H3D offers assays as a service related to these processes and these offerings include:

  • Primary Assays
    • Lipophilicity LogD
      • Most commonly quantified by measuring the extent of distribution of a substance in the aqueous (hydrophilic) vs. hydrophobic (lipophilic) phase
      • High lipophilicity often contributes to high metabolic turnover, low solubility and poor oral absorption, and highly lipophilic compounds have a tendency to bind hydrophobic compounds other than their desired target, thereby increasing the chance or incidence of undesired side effects of a candidate compound
    • Aqueous Kinetic Solubility
      • pH 7.4 or 6.5
      • Solubility is one of the most important parameters to achieve desired circulating concentration of a drug candidate in systemic circulation for a desired pharmacological response; it is the maximum amount of a substance that will dissolve in an amount of solvent at a specified temperature and pH
    • Biorelevant Solubility
      • Simulates composition and pH of fasted and fed state gastrointestinal (GI) fluid states for biorelevant dissolution testing
      • pH 6.5 FaSSIF: fasted state simulated intestinal fluid
      • pH 6.5 FaSSGF: fasted state simulated gastric fluid
      • pH 2.0 FeSSIF: fed state simulated intestinal fluid
  • Secondary Assays
    • Metabolic stability
      • Microsomal stability (1 or 5 pt assay)

      • Hepatocyte stability

      • S9 stability

      • Metabolite identification

        Hepatocytes and liver subcellular fractions (microsomes and S9) contain a variety of enzymes that metabolize pharmaceutical drugs. This data can be used to estimate the clearance of compounds in vivo. Data is reported as the amount of compound metabolised during the experiment, in vitro half-life, and in vitro clearance. The assay can be performed in human, dog, hamster, rat and mouse hepatocytes or microsomes.
        The same experiment format can also be used to identify metabolites that contribute to the observed clearance allowing targeted medicinal chemistry efforts to improve metabolic stability.

    • Permeability
      • PAMPA
      • Parallel Artificial Membrane Permeability Assay (PAMPA) is an in vitro, non-cell based model of passive, transcellular permeation used as a screening tool for evaluation of a test drug's permeability across various experimental membranes
    • Caco-2 permeability assay
      • Caco-2 cells are an immortalized cell line of human colorectal adenocarcinoma cells that primarily serves as an experimental model of the intestinal barrier
    • Plasma Binding Protein (PPB)
      • human
      • The main influence of plasma proteins on drugs in in their distribution, and plasma proteins can bind to drugs and significantly affect their biological half-life; relationships between bound and unbound drug particles in circulation can cause a clinically significant change in the pharmacologic action of a drug or drug candidate
    • Plasma Stability
      • Measures the extent of a compound's stability in plasma, where degradative enzymes and molecules surround experimental or established drug candidates; can be used to evaluate a panel of experimental compounds for prioritization in future in vivo studies
    • Blood Stability
      • Evaluates stability of a compound in whole blood
    • Blood to Plasma Ratio
      • Ratio of the concentration of a compound or drug in whole blood vs. the concentration in plasma, and provides an indication of a compound's binding to erythrocytes and subsequent potential for toxicity to RBCs
      • Indirectly indicates the potential for accumulation of the drug in red blood cells (RBCs)
    • Chemical stability
      • Provides testing regarding how quality of a candidate compound or drug substance varies over a specific period of time under the influence of environmental factors such as temperature, humidity, and light; used to calculate the rate of clearance of a test compound over time in microsomal incubations
  • Tertiary Assays
    • Metabolic Stability S9
      • human only, including 2 conditions
      • S9 is a liver extract (organ tissue homogenate) that contains active enzymes including P450 (post-mitochondrial supernatant fraction) and simulates hepatic activity in in vitro assays; used to assess metabolic microsomal and/or hepatocyte stability to provide insight into clearance
    • Metabolite Identification (Met ID)
      • in vitro; human, rat, and mouse
    • CYP Inhibition IC50
      • 3A4, 2D6, 2C19, 2C9
    • Microsomal Binding
      • human, rat, dog or mouse
      • Correcting for non-specific in vitro binding of microsomes is important for accurate and useful prediction of in vivo pharmacokinetics from in vitro drug metabolism data
    • Hepatocyte Stability
      • human, rat, dog or mouse
      • hepatocytes are functional liver cells with a full complement of drug metabolizing enzymes (both Phase I & II enzymes). Data from these assays can be scales to in vivo clearance values that capture the contribution of hepatic metabolism.
  • Toxicity Assays
    • Cytotoxicity Single Point
      • (CHO) % inhibition, 96-well plate
        • Chinese hamster ovary (CHO) cells widely used in toxicity studies
    • Cytotoxicity Single Point
      • (Vero) % inhibition, 96-well plate
        • Vero is a non-human cell line (derived from monkey kidney cells) widely used for screening purposes for bacterial toxins, viruses, and parasite studies
    • Cytotoxicity IC50
      • CHO
      • Vero
      • HepG2: Human hepatoblastoma cell line commonly used in drug response, metabolism and hepatotoxicity studies
      • High Concentration 

Data from these assays can be used for lead optimization and drug candidate evaluation and results from these assays thereby inform key decision making and experimental design of human and/or animal in vivo studies.

Assay Group Assay Specifications
Primary Assays  
Lipophilicity LogD  
Aqueous Kinetic Solubility pH 7.4 or 6.5
Biorelevant Solubility pH 6.5 FaSSIF, FaSSGF, pH2 FeSSIF
Secondary Assays  
Metabolic Stability Microsomes 5 pt
Metabolic Stability Microsomes 1 pt
Permeability PAMPA
Plasma protein binding (PPB) human
Plasma Stability  
Blood Stability  
Blood to Plasma Ratio  
Chemical Stability  
Tertiary Assays  
Metabolic Stability S9 human only, including 2 conditions
Metabolite Identification in vitro; human, rat, and house
CYP Inhibition IC50 3A4, 2D6, 2C19, 2C9
Microsomal Binding human, rat, dog, or mouse
Hepatocyte Stability human, rat, dog, or mouse
Cytotoxicity Assays  
Cytotoxicity Single Point (CHO) % inhibition, 96-well plate
Cytotoxicity Single Point (Vero) % inhibition, 96-well plate
Cytotoxicity IC50 CHO
Cytotoxicity IC50 Vero
Cytotoxicity IC50 HepG2
Cytotoxicity High Concentration
ADMET Assays (Physicochemical Profiling & Toxicity)