In the collagen base, the screen compounds (TiO2 and ZnO) and natural antioxidants (flavonoids) are introduced in 2-8% proportion. Photoprotective effects of creams have been followed in vitro by sun protection factor (SPF) determination, in correlation with the antioxidant activity. The screen substances tested into collagen base show the influence of the particle size on the SPF. During the irradiation process, the couples TiO2+flavonoids produce the amplification of the SPF value, due to the photocatalitic effect of the TiO2 pigment and bis- ethyl- hexyloxiphenol - metoxiphenyltriazine (BEMT). The cream with TiO2, BEMT and flavonoids offer photoprotection on both UVA and UVB domains.