PREDICTION OF OCULAR IRRITATION POTENTIAL OF AIR CARE PRODUCTS USING IN VITRO TOPICAL APPLICATION ASSAYS.

Air care products contain high concentrations of fragrance materials which are generally aqueous insoluble. Predicting the ocular irritancy potential of this product class has been difficult and unreliable using dilution-based assays. This problem suggested that to properly model in vivo exposures, the neat test material must be applied directly to the test tissue. This study by S.C. Johnson and Son, Inc. and Microbiological Associates, Inc. sought to determine the utility of the EpiOcular™ human tissue construct (MatTek Corporation) for prediction of ocular irritancy potential of air care formulations and ingredients. The responses of the EpiOcular construct were also compared to those of the Skin2 ZK1200™ construct (Advanced Tissue Sciences). Sample formulations were prepared which spanned the expected irritancy range for this product class (Draize MMAS ranging from 4.7 to 52.3). Tissues were treated topically with 100 ul/tissue (EpiOcular) or 25 ul/tissue (ZK1200) of neat test material. Tissue viability was measured against time of exposure to determine the exposure time required to reduce viability to 50% of controls (ET50). MTT reduction was used to determine tissue viability in both cases. In general, the EpiOcular construct proved to be more robust than the ZK1200 and gave ET50 values which better resolved the toxicity over the full range of irritancy potential. When the EpiOcular log ET50 values were plotted against the log MMAS values the r2 value was 0.73. The slope and intercept of this regression were very similar to the prediction model (log ET50 vs. predicted MMAS) proposed by the MatTek Corporation.

Air care products, Draize prediction model, Draize scores, Draize tests, Endpoints, MTT, EpiOcular, Eye irritation, MTT, MTT ET-50 tissue viability assay, MTT assay, Ocular irritancy testing, Ocular irritation, Ocular irritation testing, Pre-validation, Prediction model, Prevalidation, Validation, Viability