International – Validation of an in vitro sun protection factor (SPF) method in blinded ring‐testing

Objective

The objective of this work was to investigate the utility of a new in vitro SPF test method in blinded ring‐testing, against new ISO acceptance criteria.

Methods

Twenty four blinded, commercial, emulsion‐type, primary sunscreen products, covering the full range of labelled SPF in Europe (SPF6 – 50+), were tested by three test institutes using the current ISO24444:2010 In Vivo SPF Test Method and simultaneously by three separate test laboratories using a new candidate in vitro SPF test method, developed under the leadership of Cosmetics Europe (CE). The resulting relationship between in vitro SPF and in vivo SPF values was then compared with acceptance criteria developed recently by the International Standards (ISO) TC217/WG7 Sun Protection Test Methods Working Group…