Sun protection effect of 2-hydroxy-4-(Octyloxy) benzophenone in sunscreen creams formulations by a combination of inorganic uv filters

Abstract

Overexposure of ultraviolet (UV) radiation, especially UVB (280-320 nm) and UVC (200-280 nm) have a harmful effect on the skin. Sunscreen such as derivatives of benzophenone can protect the skin from these detrimental effects. In this research, we evaluated the potency of 2-hydroxy-4-(octyloxy) benzophenone as a sunscreen and improved the ability by combining it with the physical blocker TiO2 or ZnO in the form of a cream formulation. We use a D-optimal mixture design to obtain the cream formulation with high Sun Protection Factors (SPF) and acceptable characteristics. Several cream formulations containing 2-hydroxy-4-(octyloxy) benzophenone and TiO2 or 2-hydroxy-4-(octyloxy) benzophenone and ZnO were prepared with concentrations of 5-10%. The creams were tested for the physicochemical parameters such as pH, color, odor, homogeneity, viscosity, and stability. The SPF was observed by spectrophotometry and the value was calculated using the Mansur equation. SPF value of 2-hydroxy-4-(octyloxy)benzophenone, TiO2, and ZnO were 25.21±0.47; 24.74±0.35; 3.20±0.05, respectively. SPF value of creams combining 2-hydroxy-4-(octyloxy) benzophenone and TiO2 were in the range of 4.140-6.326. Furthermore, the SPF value of creams combining 2-hydroxy-4-(octyloxy) benzophenone and ZnO were in the range of 3.609-8.052. The creams meet the requirement of physicochemical properties with acceptable characteristics. They were stable when the creams kept at room temperature for one month. In this current study, the formulation of sunscreen creams with high SPF and acceptable characteristics obtained by a combination of 10% 2-hydroxy-4-(octyloxy) benzophenone and 5% titanium dioxide or ZnO.