Eye Irritation Time-to-Toxicity Test using Reconstructed Human Corneal Epithelium (RhCE) Models

The ocular irritation potential of formulations, products, ingredients, and chemicals can be evaluated using in vitro reconstructed human corneal epithelium (RhCE) models, such as the EpiOcular™ (MatTek Corp.) and SkinEthic HCE (EPISKIN) organotypic 3-D tissue constructs.  Whether evaluating ultra-mild cosmetics and personal care products, or rank ordering the irritation potential of candidate formulations and ingredients, we can provide custom Ocular Screening protocols to best meet your testing goals.

The Ocular Screening protocols use a time-to-toxicity procedure to determine the test material exposure time that induces a 50% reduction in viability, relative to the negative control (ET50 or t50).  This value can be used to evaluate the degree of irritancy of the test material (non/minimal, mild, moderate, severe/extreme).

For regulatory requirements or GHS classification needs, we recommend performing the Eye Irritation Test.

Quick Facts
  • In vitro RhCE models are made from human-derived cells, which are cultured on specially designed cell culture inserts.  The cells are cultured to form a multi-layered structure which closely models the corneal epithelium.
  • 3-D reconstructed epithelial tissues model the barrier properties of the native epithelium, thus providing a relevant platform for modeling the permeation kinetics of chemicals and ingredients.
  • Since test formulations can be applied topically at full formulation strength, tissue exposures occur just as they do in vivo.
  • The inclusion of benchmark chemicals or formulations can greatly improve the irritation assessment of tested materials.
  • The Ocular Screening protocols are ideal for testing materials ranging from very mild to moderate eye irritants.
  • The assay is compatible with both water soluble and insoluble raw materials, as well as mixtures and formulations.
  • In vitro RhCE models are suitable for testing liquids, creams, pastes, highly viscous materials, and solids.
  • Cytokine expression analyses may be included to further discriminate among extremely mild formulations (suitable for products intended for sensitive individuals).
  • Based upon an eye irritation testing strategy developed at IIVS, a custom EpiOcular protocol is approved for determination of eye irritation potential of anti-microbial cleaning products in the U.S. EPA’s Office of Pesticide Programs under the U.S. EPA classification and labeling system (US EPA, 2013).

Specialized protocols may be prepared as requested through consultation with the Study Director.

Please contact IIVS for more information on Ocular Screening and how it may be suitable for your organization’s testing needs.

3D Tissue: Each tissue is comprised of human cells in a 3-dimensional multi-layered epithelium. Upon receipt, tissues are inspected and then transferred to pre-labeled plates containing pre-warmed medium. The plates are then placed in a humidified incubator to equilibrate the tissues.