Overview of proficiency testing results for the in vivo determination of sun protection factor.

A sunscreen product is allowed to be marketed if a protection is provided against ultraviolets (UV) including UVA rays and UVB rays expressed by the sun protection factor (SPF). UVB is radiation that is in the region of the ultraviolet spectrum which extends from about 290 to 320 nm in wavelength and that is primarily responsible for sunburn, ageing of the skin, and the development of skin cancer. Thus, since April 2009, the Bureau Interprofessionnel d'Etudes Analytiques (BIPEA) set up a proficiency testing scheme (PTS) for the determination of SPF in vivo of sunscreen products according to ISO 24444 standard [Cosmetics - Sun protection test methods - in vivo determination of the sun protection factor (SPF)] to evaluate the analytical performances of laboratories on these analyses.

New formulation technology to boost sun protection.

Objective: As every skin type worldwide is concerned by photoprotection, with consumers preferring cosmetic elegant and efficient sunscreen products, we aim at developing the most performant and desirable sun care products.

Methods: We selected an interesting polymer, abbreviated AAHCP and designed scanning electron cryomicroscopy (cryoSEM), small angle and wide angle X-ray scattering and confocal laser scanning microscopy studies to understand its behaviour in solution and in simplex sun care formulations. This allowed us to develop innovative sunscreen formulation technology that was demonstrated by in vitro and in vivo photoprotection methods.