The FDA Dental Plaque Subcommittee's draft report recommendations regarding the use of alcohol in mouthwashes need more scientific explanation, NDMA Pharmacology and Toxicology Director Patrice Wright, PhD, stated at the Nonprescription Drug Advisory Committee's final dental plaque panel meeting in Rockville, Md. Dec. 2-3.

Although Wright noted the Nonprescription Drug Manufacturers Association does not question the panel's conclusions, she said the draft lacks appropriate detail in terms of industry study results and meeting presentations from which the group reached its conclusions.

For example, the draft report does not specifically mention "any of the review or any of the commentary" from a June 1996 FDA OTC Plaque Subcommittee workshop discussing the issue, Wright pointed out ("The Tan Sheet" June 10, 1996, p. 3).

"By omitting this information, the scientific support and knowledge for the conclusions is missing and the panel's report is weakened and open to challenge," she maintained.

The panel report was released by FDA Nov. 2 in the form of a draft advance notice of proposed rulemaking that would establish an OTC monograph for products that reduce or prevent dental plaque and gingivitis. Industry comments on the draft were heard by the subcommittee at the day-and-a-half meeting.

"A more detailed critical evaluation of the epidemiology studies of mouthwash and oral cancer is needed," NDMA and the Cosmetic, Toiletry & Fragrance Association say in Nov. 24 joint comments to the panel.

The draft also fails to provide information on possible confounding effects from tobacco use and alcohol beverage consumption, study findings that argue against a causal relationship and discussions on the "relevance" of mechanistic studies on involving ethanol and increased oral cancer risk, the trade groups maintain.

At the 1996 Plaque Subcommittee meeting, the group unanimously agreed that submitted data alleviated members' "previous concerns about the safety of those alcohol-containing mouthrinses as presently formulated" ("The Tan Sheet" June 10, 1996, p. 1).

The subcommittee notes in the draft report that "several researchers have implicated high alcohol-content mouthwashes as a possible cause of oral/pharyngeal cancer" and points to the need for further studies to determine the relationship between alcohol-containing mouthwash and oral cancer.

The draft report references data presented at the June meeting, but does not detail the specific studies.

The draft offers two recommendations: "All mouthwashes should be labeled in a readily readable manner with the alcohol concentration in percent; e.g., 'contains__% alcohol' on the principal display label," and "scientifically sound studies to determine the relationship between high alcohol-content mouthwashes and oral/pharyngeal cancers should be instituted and completed in a timely manner."

NDMA and CTFA believe the draft is "not a complete report," Wright stated. The document "does not adequately support the panel's conclusions [or] reflect the totality of the deliberations," she added.

"We are not asking for changes at this stage for the panel's recommendation. We are looking to make this as complete as possible." NDMA Senior VP and Director of Science & Technology William Soller, PhD, stressed. The subcommittee should forward its recommendations to FDA only when it is "satisfied as a panel that [the document] captures everything that you want it to capture," he commented.

Soller also requested an extension of the comment period beyond the three weeks since the draft was made available. "We'd like to suggest...there would be an additional limited time period that might be kept open after this meeting," he said, noting an extension would help the subcommittee "ensure that the numbers quoted are accurate and that the deliberations that have taken place are accurately reflected."

FDA hopes to finish modifications to the report within two to three months, Center for Drug Evaluation & Research Division of OTC Drug Products Liaison Robert Sherman stated at the close of the meeting.

An additional issue in need of consideration by the panel is the draft's handling of hydrogen peroxide, NDMA's Wright asserted. The subcommittee's report, she stated, showed inconsistencies regarding the safety and effectiveness classifications of the ingredient.

At one point in the report, the subcommittee concludes hydrogen peroxide should be classified as Category I for safety and Category III for efficacy. However, the draft later says "there is a lack of well-controlled studies of sufficient length to draw firm conclusions regarding the safety and effectiveness of hydrogen peroxide."

To help avoid confusion, NDMA/CTFA requested the insertion of a chart for ingredients with safety and efficacy classifications for each reviewed ingredient (see chart below).

Again pointing to the need for additional references to specific scientific data, Wright suggested industry studies involving hydrogen peroxide should be included in the report. NDMA/CTFA's amended version would "summarize the missing information briefly, as far as the studies that were missing and the presentations that were made."

The trade groups ask that three presentations on the safety of hydrogen peroxide be included in the final report. "These presentations provided additional information which supported the subcommittee's conclusion that hydrogen peroxide is safe in concentrations up to 3%," the comments note.

Although the panel did not discuss changes to be made to the hydrogen peroxide section of the report, subcommittee member Eugene Savitt, DMD, volunteered to rewrite the section with consideration of industry's comments.

As a final note, Wright asserted hydrogen peroxide and alcohol mouthwash are only examples of areas of the draft report that need changes or additions. "We could talk about stannous [fluoride], we could talk about essential oils, we could probably talk about any one of the ingredients" in the draft recommendation, she said.

"There is quite a lot of work to be done to look at each of these ingredients and make sure that the whole process has been fully reflected" before a final dental plaque monograph can be finished, she concluded.

NDMA and CTFA also suggest many format-type changes to the draft report. For example, the groups urge in their comments that the alcohol section of the draft be moved from among active ingredients to the end of the document as an inactive ingredient.

FDA says many of these suggestions, which range from substantive additions to grammatical changes, have been or will be addressed for the final version of the document.

Dental Plaque Subcmte. Draft Needs Further Scientific Data - NDMA/CTFA

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