IN VITRO METHODS FOR ASSESSING OCULAR IRRITANCY OF COSMETICS.

This study by scientists at Institute Dr. Schrader Creachem GmbH demonstrated that MatTek’s EpiOcular in vitro human cornel tissue equivalent can be used to test the ocular irritancy of a variety of products and has an advantage versus other in vitro test methods because the test materials, including cosmetics, are analyzed directly on human tissues, providing an objective, distinctive classification for assessing ocular irritancy. Varieties of in vitro test protocols serve as replacement for the Draize Test to assess ocular irritancy of cosmetics. Five protocols (BCOP, HET/CAM, ICE, CEET and IRE) are validated and accepted by legal authorities. Validation is underway for the the EpiOcular™ (MatTek Corp.) assay. Additionally, the RBC test is a widespread method to assess the irritating potential of surfactants. Presently, there exists neither a COLIPA nor an OECD test guideline regarding how to assess ocular irritancy in vitro. In this study, scientists at Institute Dr. Schrader Creachem GmbH compared the feasibility of three in vitro methods (R8O, HET/CAM and EpiOcular™ Assay) to assess the ocular irritancy of cosmetics. Five common purchasable surfactants with known in vivo rating were tested concurrently. Conclusions: Although the RBC assay is often used, it is only suitable for anionic surfactants and susceptible to interfering elements from the test material. Therefore, testing of final formulations is limited. The MET/CAM test proved to be practicable for cosmetics and shows good correlation with the recognition of highly irritating and non-irritating substances. Nevertheless, it is based on a subjective rating and thus missing an objective endpoint. The EpiOcular™ assay is suitable for various test products and has the advantage that test materials can be analyzed directly on human tissues. Scientists at Institute Dr. Schrader found EpiOcular™ to be a valuable tool in the routine analysis of formulations and single substances. For a correct classification, a suitable test (EpiOcular) protocol has to be chosen prior the testing. For market products containing surfactants, the Neat Method showed a good product differentiation whereas for pure surfactants the Dilution Method should be selected. Simultaneous to measuring tissue viability, additionally parameters e.g. LDH, PGE-2 and IL-1a can be quantified to obtain further information about the irritation potential and possible inflammatory processes. In conclusion, to obtain a usable product rating, the type of test material as well as the test parameters (pH-value, dilution etc.) have to be carefully considered. The MET/CAM test is a cost-effective alternative, whereas testing on human tissue equivalents such as EpiOcular™ enables an objective distinctive classification for assessing ocular irritancy of cosmetics.

COLIPA, Dilution protocol, Draize test, EpiOcular, EpiOcular Assay, Neat method, OECD, Occular irritancy of cosmetics, Surfactants

Disodium Cocoyl Glutamate, Laureth-7 Citrate, Lauryl Glucoside, Sodium Laureth Sulfate, Sodium Lauryl Glucose Carboxyte