Assessing the skin irritation potential of facial tissues

Our primary objective was to develop a short-term test system for evaluating differences in the irritant effects of facial tissues that could be used as a screening tool for product improvements with regard to skin mildness. The strongest evidence for product superiority is based on a combination of data: 1) subjective (i.e., panelist or consumer preference with regard to the attributes important to skin effects) and 2) expert clinical evaluation (i.e., a quantitative measure of product superiority by a third party, such as erythema and dryness scores). In this assay, both measures were evaluated.

In three separate studies, facial tissue products were compared with a currently marketed product with a lotion coating (product A). Test materials included products B and C (each without a lotion coating) and product G (a facial tissue product coated with a developmental lotion). Panelists (15-16 per study) were assigned one tissue product to use on one side of the nose and the other product on the alternate side. They were asked to wipe the tissue from the nasal bridge to the upper lip for 10 wipes every 20 minutes for a total of 170 wipes (17 series) daily on Monday through Thursday. Prior to the first test product application, the integrity of the skin on the nasolabial folds was compromised by tape stripping using successive applications of occlusive tape. Erythema and dryness were scored by a trained grader every morning and afternoon. Panelists were asked specific questions about product preference at the end of each day.

Based on the statistical analysis, the reported sensory effects were the most reliable measure of product differences, with panelists showing a clear preference for the lotioned product (A) over the nonlotioned products (B and C), and slight preference for product A over the other lotioned product (G). The clinical evaluation measures of irritation (erythema and dryness) were less consistent in detecting product differences. Those differences that were detected were generally consistent with the sensory effects data.

This assay detects significant panelists' preferences and, therefore, forms a useful part of the arsenal for evaluating skin effects and claims support. However, without further modification, the assay is not sufficiently robust to reliably detect differences in the clinical measures of irritant effects (erythema and dryness).