Figure 1. The TI value of surfactant. The TI value on the vertical axis indicates the relative value of the effect on the skin barrier function with water as the standard (TI = 1). Values represent mean and standard error (SE) obtained from 4 or more experiments. 1: Sodium laurate, 2: Sodium lauryl sulphate, 3: Dimethyldistearylammonium chloride, 4: Trimethylstearylammonium chloride, 5: Lauryl Dimethylaminoacetic acid betaine, and 6: Cocamidopropyl betaine. (*) is the quaternary ammonium salt type surfactant.