COLIPA PROGRAM ON OPTIMIZATION OF EXISTING IN VITRO EYE IRRITATION ASSAYS FOR ENTRY INTO FORMAL VALIDATION: TECHNOLOGY TRANSFER AND INTRA/INTER LABORATORY EVALUATION OF EPIOCULAR ASSAY FOR CHEMICALS.

This study by scientists at Mary Kay, Inc., COLIPA (European Cosmetics Association), Procter & Gamble Co. and MatTek Corp. demonstrated that MatTek’s EpiOcular in vitro human corneal tissue equivalent is a very accurate and reproducible in vitro model for the determination of human eye irritation. Study Results: 99.7% agreement in irritation prediction in 298 independent eye irritation trials performed in seven (7) different laboratories, four (4) EU labs and three (3) US Labs. These results not only confirmed interlaboratory test reproducibility, but once again demonstrated MatTek’s proven ability to ship our in vitro reconstructed human tissue equivalents internationally with no negative impact on performance. The European Union will ban in vivo eye irritation tests on ingredients for cosmetic products after March 2009. COLIPA, the European Cosmetics Association, is actively working to bring in vitro eye irritation tests to formal validation with ECVAM. This poster details the COLIPA program on technology transfer and reproducibility of MatTek’s EpiOcular™ assay as one of the two human reconstructed tissue assays. This EpiOcular protocol differs from previous time-to-toxicity protocols in that it uses a single exposure period for each chemical and a prediction model based on a cut-off in relative survival (≤ 60% = irritant (I) (R36 and R41); >60% = non-classified (NC)). Test substance exposure time is 30 minutes with a 2-hour post-exposure incubation for liquids and 90 minutes with an 18-hour post-exposure incubation for solids. After the post-exposure, tissue viability is determined by tetrazolium dye reduction (MTT). Combinations of 20 coded chemicals were tested in seven (7) laboratories. A standardized protocol and laboratory documentation were used by all laboratories. MatTek provided initial training and then each laboratory operated independently during the technology transfer study. Twenty liquids (11 NC/9 I) recommended by ECVAM plus 5 solids (3 NC/2 I) were selected so that both exposure regimens could be assessed. Concurrent positive (methyl acetate) and negative (water) controls were tested in each trial. Chemical decoding occurred only after study completion. In all, 298 independent trials were performed and demonstrated 99.7% agreement in prediction (NC/I) across the laboratories. Coefficients of variation for the % survival of tissues across laboratories was generally modest (Using these data, a formal submission was sent to ECVAM in support of the protocol’s entry into a formal validation study.

COLIPA, Cosmetic products, ECVAM, EpiOcular, European Cosmetics Association, European Union, In vitro eye irritation tests, In vivo eye irritation tests, R36, R41, Tetrazolium dye reduction (MTT)