Titanium Dioxide (E171 Grade) and the Search For Replacement Opacifiers and Colorants: Supplier Readiness Survey, Case Studies and Regulatory Perspective.

Titanium dioxide (TiO2) is used primarily as an opacifier in solid dosage forms and is present in the majority of tablet and capsule dosage forms on the market. The IQ* TiO2 Working Group has previously shown that titanium dioxide has unique properties which are necessary for its function in these formulations and noted that, as the potential replacements lack the semi-conductor properties, high refractive index and whiteness of E171, it might be hard to replicate these properties with alternative materials. In this paper we detail the results of readiness surveys and practical assessments that have been conducted with alternative materials by IQ member companies.