In vitro eye irritation testing models may play pivotal role in effort to pursue mild baby cleansers

In recent years, mild baby cleansers have experienced ever-growing demand from caregivers. In the meantime, formulation developers are in practical need for a method(s) to screen mild formulations. In the present study, we aim to repurpose the HET-CAM and SkinEthic™ models to further classify in vivo nonirritant baby cleansing formulations into mild and less mild categories. Both methods were modified to best describe the samples' irritation potential. The results showed that both models successfully classified the formulations into mild and less mild categories according to our customized criteria. For the HET-CAM, the medians of mean irritation scores (IS) were 3.0 for mild formulations (with 0 ≤ mean IS ≤4.5), and 5.0 for less mild formulations (with mean IS values all equaled 5), respectively. And for the SkinEthic™ model, the median relative viabilities were 69.46% for less mild formulations (with 46.80% ≤ mean relative viability ≤84.76%), and 99.96% for mild formulations (with 90.57% ≤ mean relative viability ≤124.58%). Thirty out of 35 formulations were predicted consistently between the HET-CAM and SkinEthic™ model. Statistical analysis of the agreement between predictions made by the two models demonstrated substantial agreement with a Cohen's kappa coefficient of 0.713 (P < 0.001). We conclude that the HET-CAM and SkinEthic™ models are promising in vitro alternatives for screening mild formulations.