showed statistically higher SPF (13.6) when compared with FB (non-ionic SEB), which presented higher thixotropy and a SPF of 9.84. The FE sample (phosphate- based SEB /PVP/EC) presented the same SPF as the FC, but had a higher thixotropy. The FB formulation (stable with higher thixotropy) showed the lowest SPF while FC (an unstable formulation with lower thixotropy) presented a higher SPF. We concluded that FE was the best formulation showing a higher SPF and stability and the study of rheology can help the development of sunscreens.