Evaluation of the sun protection factor of sunscreen containing rosehip oil as a natural UV -Protective Agent

Sun protection factor (SPF) has become the globally recognised standard for evaluating the efficacy of sunscreens as it provides an estimate of the duration of safe sun exposure before erythema occurs. In this study, a two-step sunscreen formulation was developed using predominantly organic materials consistent with the principles of green chemistry, with the only inorganic ingredient being non-nano zinc oxide. Rosehip oil (Rosa canina L.) was obtained by soaking the plant material in olive oil for one month and enhancing the extraction by regular stirring and mechanical crushing. The resulting oily extract was then incorporated into a sunscreen formulation containing beeswax and non-nano zinc oxide, resulting in a stable, high-performance cream with 92% efficiency. The in vitro SPF value was determined according to the spectrophotometric method described by Mansur et al., by measuring the absorption of olive oil, rosehip oil, and the formulated cream in the range of 290–320 nm using UV–Vis spectrophotometry. Olive oil had an SPF of 7.83, while rosehip oil had an increased SPF of 11.4. The sunscreen formulation in particular achieved a significantly higher SPF value of 28.67, which corresponds to blocking more than 95% of UVB radiation. These results emphasise the potential of rosehip oil to improve the sun protection performance of natural oil-based sunscreens.