Assessment of the Cytosensor Microphysiometer Assay in the COLIPA In Vitro Eye Irritation Validation Study.
J W Harbell1, R Osborne, G J Carr
1Microbiological Associates, Inc., Rockville, MD, USA.
Summary
The Cytosensor microphysiometer assay shows promise for predicting ocular irritation of cosmetic ingredients, particularly surfactants. However, its accuracy is limited for certain chemicals like acids and bases, requiring model revisions.
Area of Science:
- Toxicology
- In vitro assays
- Cosmetic science
Background:
- Ocular irritation testing is crucial for cosmetic safety.
- Existing methods may have limitations in accuracy and ethical considerations.
- In vitro assays offer a potential alternative to traditional testing.
Purpose of the Study:
- To validate the Cytosensor microphysiometer assay for predicting ocular irritation potential.
- To evaluate the assay's performance across various cosmetic ingredients and formulations.
- To assess the reliability and reproducibility of the assay within a collaborative study.
Main Methods:
- The Cytosensor assay was used to measure the metabolic rate of L929 cells upon exposure to test materials.
- The dose inducing a 50% decrease in metabolic rate (MRD(50)) was determined.
- The assay was evaluated in the COLIPA ocular irritation validation study.
Main Results:
- Only 29 out of 55 materials could be tested due to solubility issues.
- The assay underpredicted irritation for acids, bases, and organic chemicals.
- The assay showed promise for surfactants and surfactant-based formulations.
- Excellent interlaboratory reproducibility was observed for MRD(50) values.
Conclusions:
- The Cytosensor assay has potential for ocular irritation assessment, especially for surfactants.
- Revisions to the prediction model are needed for broader applicability.
- Solubility limitations and underprediction of certain chemical classes require further investigation.
