Related Experiment Video
Updated: May 30, 2026
17:28
Human Pluripotent Stem Cell Based Developmental Toxicity Assays for Chemical Safety Screening and Systems Biology Data Generation
Published on: June 17, 2015
Validity and reliability of in vitro systems in safety evaluation
Environmental Toxicology and Pharmacology
|July 26, 2011
Summary
In vitro data can refine safety factors in risk assessment by evaluating toxicodynamics, improving inter-species comparisons. This approach aids in replacing default safety factors with chemical-specific data, enhancing human health risk evaluations.
Area of Science:
- Toxicology and Pharmacology
- Risk Assessment
- In Vitro Methods
Background:
- Current risk assessment relies on 10-fold safety factors for inter-species and inter-individual variability.
- Toxicokinetics (chemical transport) is measurable in vivo, while toxicodynamics (target tissue sensitivity) is amenable to in vitro study.
- Human data is crucial for replacing default safety factors in risk assessment.
Purpose of the Study:
- To explore the contribution of in vitro data to refining safety factors in risk assessment.
- To differentiate the roles of toxicokinetics and toxicodynamics in safety factor application.
- To assess the potential of in vitro methods to replace default safety factors with chemical-specific data.
Main Methods:
- Utilizing in vitro investigations to assess toxicodynamics (target tissue sensitivity).
- Comparing in vitro toxicodynamic data with in vivo toxicokinetic data.
- Analyzing the potential for in vitro human tissue data to inform variability in target organ sensitivity.
Main Results:
- In vitro data can quantify inter-species differences in toxicodynamics, potentially replacing default safety factors.
- Toxicodynamics is a key area where in vitro data can contribute to risk assessment refinement.
- The use of human tissues in vitro requires substantial specimens to represent in vivo variability.
Conclusions:
- In vitro toxicodynamics offers a valuable tool for enhancing the precision of risk assessment by replacing default safety factors.
- Chemical-specific inter-species differences in toxicodynamics can be better understood through in vitro studies.
- Further research with human tissues is needed to fully leverage in vitro data for assessing human variability in toxicodynamics.
Related Concept Videos
01:10In Vitro Drug Release Testing: Overview, Development and Validation
In vitro dissolution and drug release tests assess how quickly and how much of a drug is released from its dosage form into an aqueous medium under standardized laboratory conditions. These tests are essential tools in pharmaceutical development and quality assurance, offering insight into the drug's performance before clinical use.During formulation development, dissolution testing identifies incomplete or inconsistent drug release issues. It also supports decisions on selecting the optimal...
01:20Drug Product Performance: In Vitro–In Vivo Correlation
In pharmaceutical development, it's crucial to establish a predictive in vitro–in vivo correlation (IVIVC) for two or more formulations to gain a comprehensive understanding of release properties. IVIVC reduces the need for costly in vivo studies and facilitates the establishment of meaningful dissolution specifications with significant cost savings and decreased regulatory burden. Furthermore, a meaningful IVIVC should predict Cmax and AUC within 20%, aligning with FDA guidance while adhering...
01:13In Vitro Drug Dissolution: Compendial Testing Models I
Compendial dissolution methods are standardized procedures defined by pharmacopeias to evaluate the rate at which a drug dissolves in a specific medium. These methods ensure batch-to-batch consistency, enable quality control, and support the prediction of drug bioavailability. They are critical for both immediate and modified-release drug products.The apparatuses used for dissolution testing differ in their design and mechanical function, but all aim to simulate the physiological environment of...
01:16In vitro Mutagenesis
To learn more about the function of a gene, researchers can observe what happens when the gene is inactivated or “knocked out,” by creating genetically engineered knockout animals. Knockout mice have been particularly useful as models for human diseases such as cancer, Parkinson’s disease, and diabetes.
01:17Equivalence: In Vitro and In Vivo Bioequivalence
Bioequivalence studies are crucial in evaluating whether new drugs can match an approved one regarding pharmacological effects and clinical performance. These studies test if drugs, despite different dosage forms, share identical plasma concentration-time profiles. Three types of equivalence are central to these studies: chemical, pharmaceutical, and therapeutic. Chemical equivalence indicates that two or more drug products contain identical active ingredients in equal amounts. Pharmaceutical...
01:23Toxicity Testing in Animals
Toxicity tests in animals are grounded on two main assumptions: first, the effects observed in laboratory animals can be extrapolated to humans, especially when adjusted for body surface area; second, high-dose exposure in animals is essential to identify potential human hazards from lower doses. This is based on the quantal dose-response concept, which faces the challenge of extrapolating results from relatively few test animals to much larger human populations. For example, a 0.01% incidence...