STM Article Repository

The present research aimed to determine the sun protection factor (SPF) values of some sunscreen formulations used in cosmetics by ultraviolet spectrophotometer. The efficacy of a sunscreen is usually expressed by the sun protection factor (SPF), which is defined as the UV energy required to produce a minimal erythemal dose (MED) in protected skin, divided by the UV energy required to produce a MED in unprotected skin. A sunscreen's ability to prevent sunburn is measured in a lab setting by its sun protection factor (SPF). The greater the SPF, the more protection the sunscreen provides against UV rays. SPF is determined by the spectrophotometric method reported by Mansur et al. Hydro-alcoholic dilutions of oils were prepared and in vitro photoprotective activity was studied by UV spectrophotometric method in the range of 290-320 nm. It was observed that the SPF values for cosmetic formulations were between 13 and 16. Among the various sunscreen formulations, SPF values were compared. The study is helpful in the selection of sunscreen formulations used in cosmetics with better safety and high SPF values. To develop sunscreens with better safety and high SPF, the formulator must understand the physicochemical principle, not only the UV absorbance of the actives but also vehicle components, such as esters, emollients, emulsifiers and fragrances used in the formulation, since sunscreens can interact with other components of the vehicle, and these interactions can affect the efficacy of sunscreens.