There are two primary forms of titanium dioxide commercially available: anatase and rutile. The rutile form is typically used in sunscreens due to its superior ability to handle UV rays and stability in the presence of UV light. The anatase form is typically used in other types of products, such as paint. Another plus of the rutile form is that its UVA protection extends past 400 nanometers, which is the upper limit of UVA.
TiO2 is also used in oral pharmaceutical formulations, and the Pharmaceutical Excipients handbook considers nano-sized TiO2 a non-irritant and non-toxic excipient. Despite the fact that TiO2 submicron- and nano-sized particles are widely used as food and pharmaceutical additives, information on their toxicity and distribution upon oral exposure is very limited.