ANTICARIES TFM: UNTESTED FLUORIDE/ABRASIVE SYSTEMS

ANTICARIES TFM: UNTESTED FLUORIDE/ABRASIVE SYSTEMS should not be included in the proposed rules, the American Dental Association (ADA) recommended in recent comments to FDA. "Abrasives can play a very critical role in the rate of release/availability of the active agent," ADA said. Therefore, "only clinically tested fluoride/abrasive systems should be eligible for review under this monograph. Untested systems should be required to supply clinical data to support efficacy." As written, the tentative final monograph for OTC anticaries dentifrices allows the marketing of a cavity-fighting dentifrice that contains any abrasive system (e.g. silica) as long as it also uses a form of fluoride listed in the monograph. The monograph does not require clinical testing of the abrasive ingredients. Under the TFM, companies are allowed to use lab profiles to assess the release rates of the active ingredient in a "steady state." ADA maintained that "this value has no meaning in examining the potential efficacy of this class of products." As a result of the "very limited nature" of the TFM's lab studies requirement, ADA continued, "there is no guarantee that the fluoride agent will be biochemically available during the very limited exposure periods associated with brushing." The ADA comments are in response to a TFM for OTC anticaries dentifrices published in June that dealt exclusively with laboratory profiles for final formulation testing of dentifrice ingredients ("The Pink Sheet" June 20, T&G-7). In 1985, FDA published the ingredient section of the TFM for OTC anticaries dentifrices. ADA also suggested that FDA modify the TFM to require the submission of animal caries and remineralization studies as part of the OTC approval process for tartar-control fluoride dentifrices. Explaining why tartar control fluoride dentifices "should be required to submit a more extensive profile review, ADA asserted that tartar-inhibiting ingredients may affect the "calcification/decalcification process associated with caries." ADA recommended that "either animal caries or remineralization studies be required...to guard against the potential inactivation of the fluoride agent by a secondary `non-therapeutic' additive." The fluoride/abrasive systems testing recommendations were prompted by two studies submitted to ADA by Procter & Gamble on fluoride equivalency and clinical superiority, according to an ADA spokesperson. The P&G studies were conducted under criteria developed at a 1987 ADA workshop. The studies concluded that Crest's sodium fluoride in a silica abrasive system at 1,100 parts per million (ppm) and 2,800 ppm was superior to equal levels of sodium monofluorophospate (MFP) in a silica system. There are no MFP/silica dentifrices on the market at the tested concentrations. Although Colgate Tartar Control Formula uses sodium fluoride, MFP is the active ingredient in other Colgate toothpastes. The ADA's Council on Dental Therapeutics ruled that P&G cannot use the study as the basis for superiority claims over any other specific dentifrice on the market. P&G can, however, claim that Crest's sodium fluoride at the ppm's tested is superior to the MFP formula used in the studies. The company is reportedly preparing a new ad campaign based on that claim. Colgate-Palmolive has received the Council's seal of acceptance for anticaries products for a sodium fluoride formula dentifrice not yet on the market.