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Absorption, Distribution, Metabolism, Excretion, Toxicity (ADMET) Platform Services

Physicochemical Profiling: ADMET at H3D

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.

Circulating human and infectious molecules conceptual model, 3d illustration
 
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
      • Microsomes 5pt
      • Microsomes 1pt
      • Human liver microsomes contain a variety of enzymes that metabolize pharmaceutical drugs and are frequently used as a test system for assays including metabolite identification (Met ID)
      • Metabolic stability is assessed in liver microsomes and defined as the percentage of a compound lost or degraded over time
    • 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
        • see above
      • Vero
        • see above
      • HepG2
        • Human hepatoblastoma cell line commonly used in drug response, metabolism and hepatotoxicity studies
    • Cytotoxicity
      • 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 Average Turnaround Time
Primary Assays    
Lipophilicity LogD   5 days
Aqueous Kinetic Solubility pH 7.4 or 6.5 4 days
Biorelevant Solubility pH 6.5 FaSSIF, FaSSGF, pH2 FeSSIF  
     
Secondary Assays    
Metabolic Stability Microsomes 5 pt 3 days
Metabolic Stability Microsomes 1 pt 3 days
Permeability PAMPA 3 days
Plasma protein binding (PPB) human 3 days
Plasma Stability   3 days
Blood Stability   3 days
Blood to Plasma Ratio   3 days
Chemical Stability   3 days
     
Tertiary Assays    
Metabolic Stability S9 human only, including 2 conditions 3 days
Metabolite Identification in vitro; human, rat, and house 3 days
CYP Inhibition IC50 3A4, 2D6, 2C19, 2C9 3 days
Microsomal Binding human, rat, dog, or mouse 3 days
Hepatocyte Stability human, rat, dog, or mouse  
     
Cytotoxicity Assays    
Cytotoxicity Single Point (CHO) % inhibition, 96-well plate 1 week
Cytotoxicity Single Point (Vero) % inhibition, 96-well plate 1 week
Cytotoxicity IC50 CHO 1 week
Cytotoxicity IC50 Vero 1 week
Cytotoxicity IC50 HepG2 1 week
Cytotoxicity High Concentration 1 week
ADMET Assays (Physicochemical Profiling & Toxicity)