Abstract
Background: Protective creams (PCs) have been studied in different models indicating a protective effect of some products. In order to compare PCs in different studies, a generic reference standard should be available. Objective: The purpose of this study was to investigate if petrolatum prevents epidermal barrier disruption induced by various irritants in a repetitive irritation test (RIT) and to assess its potential as a standard reference product. Methods: White petrolatum was evaluated against a set of 4 irritants [10% sodium lauryl sulphate (SLS), 1% sodium hydroxide (NaOH), 30% lactic acid (LA) and undiluted toluene (TOL)] in the RIT. Twenty subjects were tested on the paravertebral skin of the mid-back. Irritation was assessed by visual scoring, transepidermal water loss and colorimetry. Results: Petrolatum was very effective against SLS, NaOH and LA irritation, and it provided a moderate protection against TOL. Conclusion: Petrolatum can be recommended as a standard reference substance against which PCs may be compared as it is effective against water-soluble and water-insoluble irritants in a standardized test procedure.