Development and Validation of an Instrument to Appraise the Tolerability, Safety of Use, and Pleasantness of a Cosmetic Product

Background: Acceptability tests are designed to demonstrate that there is no chance that cosmetics would irritate or distress users in day-to-day situations. Objectives: to develop and validate a tool or scale that dermatologists, general practitioners, and other healthcare professionals can employ to assess a cosmetic product’s tolerability, safety of usage, and pleasantness. Methods: A three-step modified Delphi technique was used in the consensus process. Two rounds of online surveys and a final face-to-face meeting were performed. Fifty experts for the Delphi panel were chosen to reflect a holistic array of expertise and perspectives in pharmacovigilance, dermatology, and cosmetic safety assessments. In round 1, 80 statements and 115 statements related to skin tolerance and cosmetic safety/efficacy, respectively, were distributed to all members of the expert panel. The expert panel was asked to rate the extent to which they agreed with each statement in the questionnaire using a 5-point Likert scale and given a chance to include a remark beside each item. A statement had to receive 80% of the panel’s approval to be accepted. Results: A total of 50 professional experts were recruited in the Delphi questionnaire rounds (response rate = 63%). The expert panel reached a consensus on 30 statements to evaluate skin tolerability and 34 statements to evaluate cosmetic safety and efficacy (agreement rate level ≥ 80%). The experts also proposed a generic, systematic approach that would allow patients to report both functional and physical symptoms in addition to those discovered during an examination (clinical signs). The confrontation of these symptoms determines whether the investigated cosmetic product is ultimately cutaneously acceptable. Conclusion: The tool that was proposed during this study offered good content validity. Future studies are recommended to test the developed tools in practice to evaluate the good skin compatibility and the safety and quality of cosmetics in the UAE and other nations.