Cassidy, S. L., Stanton, E. Dow Corning Toxicology Laboratory, Midland, MI, USA. Society of Toxicology Annual Meeting, Anaheim, CA.

There are increasing efforts towards the development of alternatives to in vivo eye irritation testing in animals for human, scientific and economic reasons. Two commercially available in vitro assays (EpiOcular™ Tissue Model OCL-100 and Skin2™ ZK-1200 Model) and a third published assay, the Bovine Corneal Opacity and Permeability Assay (BCOP), were used to assess the eye irritancy potential of several organosilicon (OS) compounds for the purpose of evaluating their suitability for testing silicone polymers and other materials. The Skin2™ ZK-1200 Model (9 OS compounds) was generally applicable for the in vitro assessment of eye irritation of liquid silicone polymers, however some effort will be required to overcome the problem of working with viscous pastes and volatile low surface tension test materials for which variable results were observed. The correlation of the Skin2™ ZK-1200 Model in vitro eye irritancy results with known in vivo data were generally good for silicone polymers, although some alkoxysilanes do not appear to give in vitro results which correspond with their in vivo irritancy. In vitro results obtained with the EpiOcular Tissue Model OCL-100 (although limited), correctly identified both irritant and non-irritant silicone polymers. The BCOP assay correctly identified 4 non-irritant (2 polydimethylsiloxanes, 1 phenyl-silsesquioxane and 1 silicone polyether) and 2 irritant aminofunctional siloxane polymers which are extensively used in personal care formulations; histological examination of the treated corneas yielded results which correlated well with the opacity and permeability end-points. All 3 models performed well and are worthy of future study with OS compounds; of the two tissue construct models, the EpiOcular Tissue Model OCL-100 had several advantages over the Skin2™ Model in that it appeared to have a better technical design, facilitating more reliable dosing of the test materials and ease of use.


Corneal epithelium, Corneal epithelium models, Cosmetic Personal Care Products, EpiOcular, Eye irritation, Ocular irritancy testing, Ocular irritation, Ocular irritation testing, Organosilicon Compounds, Phorbol Myristic Acetate (PMA)

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