Fluoride in OTC Products by Ion Chromatography

Fluoride is commonly used in dental products to help prevent tooth decay. When fluoride is present in high concentrations, these products are regulated by 21 CFR 355. Three fluoride compounds used in over the counter (OTC) anti‐cavity dental products are sodium fluoride, stannous fluoride and sodium monofluorophosphate (MFP). The assay of fluoride in these active ingredients and finished formulations are determined by manual titration, or by ion‐selective electrodes. As a part of USP’s global monograph modernization initiative, an alternative selective and sensitive method has been developed and validated – ion chromatography (IC). The proposed IC method can also be used for the identification test as an alternative to the wet chemistry method.