In Vitro Tests

 Irritation: EpiDerm and EpiOcular Assays

Standard irritation assays make use of human three dimensional tissue equivalents (MatTek's EpiDerm and EpiOcular tissues).  The models allow for test materials to be applied topically, which facilitates their use with solid and insoluble materials.   The endpoint for this assay is the determination of an EC50 time (the time that it takes for tissue viability to be reduced to 50%), from which the irritation potential of the material can be predicted.  Additional endpoints include assaying for chemical mediators of inflammation such as IL-1alpha and PGE2.

EpiOcular Predicted In Vivo Irritancy

ET50 (minutes)	In Vivo Irritancy	Draize Score
> 240	Non-irritant	0
15.7-240	Minimal	0.1 - 15
7.9-15.6	Mild	15.1 - 25
3.1-7.8	Moderate	25.1 - 50
1.6-3.1	Severe	50.1 – 80
<1.6	Extreme	80.1 - 110