Butyrospermum parkii butter increased the photostability and in vivo SPF of a molded sunscreen system

Background Ultraviolet (UV) radiation exposure is related to skin and lip tumors. Therefore, the development of photoprotective lipstick formulations is of utmost importance. Aims Considering the biological properties of Shea butter (Butyrospermum parkii), we assessed its potential as an adjuvant in a molded lipstick sunscreen system by in vivo tests and photostability. Patients/Methods Shea butter was used in a photoprotective lipstick formulation at two different concentrations (10.0% and 15.0% w/w) associated with ethylhexyl methoxycinnamate (EHM) and titanium dioxide. Skin compatibility was assessed in vivo. The in vivo SPF value was determined according to the current recognized method. Additionally, the photostability of EHM was determined by high-performance liquid chromatography. Results By the cutaneous compatibility, the product presented no interference with skin barrier and no adverse reactions, thus proving its safety. The in vivo SPF assay showed that the highest concentration of Shea butter increased the in vivo SPF value of the sample by 35%, demonstrating it to be a booster in photoprotective lipstick formulations. Also, Shea butter was proved to enhance the photostability of EHM, a commonly used UVB filter available in several countries. Conclusion Shea butter increased the photostability and in vivo SPF of a molded lipstick sunscreen.