The Acute Oral Toxicity And Biodistribution Of Sunscreen Formulations Containing Zinc Oxide And Titanium Dioxide Nanoparticles In Mice

Due to their unique physical and chemical properties, nano-sized Ti O2 and Zn O have broad potential application in the field of sunscreen. They are likely to enter human body through different exposure pathways, such as skin exposure and ingestion for children, which imposes potential risks on human health. Therefore, it makes the research of its acute oral toxicity very critical and meaningful.In this paper, we prepared four different kinds of sunscreen formulations according to the typical sunscreen formula by using nano-Ti O2 and Zn O particles. The acute oral toxicity is evaluated by one week intragastric administration. The results showed that average size of Ti O2 NPs is 58×13 nm and that of Zn O NPs is 30~270 nm. The purity of these nanoparticles is more than 95% according to XRF analyses. Based on the XRD patterns, Ti O2 NPs are rutile and Zn O NPs are wurtzite structure. They are coated by a thin layer of silicon-related substance. Throughout the experiment, no significant differences are found in body weight between the control group and treatment ones. Biodistribution experiment showed that Ti O2 and Zn O NPs didn’t retain in main organs. However, histopathological lesions indicated that Zn O and Ti O2 NPs in sunscreens damaged the liver of mice and cause inflammatory cells infiltration and edema in a dose-dependent manner. Furthermore, the blood biochemical parameter(AST、ALT、ALP、TBIL and BUN) which evaluates liver and renal function, indicated that liver function was affected while renal function not. We conducted animal experimentation with pure Ti O2 and Zn O NPs by small dose( ≤ 100 mg/kg) for 30 consecutive days by intragastric administration. However, the blood biochemical parameter indicated liver function suffered little influence. It was illustrated that liver and renal function was not damaged by nanoparticles.