When is a tooth whitener a cosmetic, and when is it a pharmaceutical or medical device product? The question has never had a clear regulatory answer, and despite the efforts of the American Dental Association (ADA) to obtain one, the US Food and Drug Administration (FDA) says it prefers-for now anyway-a case-by-case approach.
In 2009, the ADA submitted a Citizen Petition to FDA requesting that the agency "review and establish an appropriate regulatory classification for tooth-whitening preparations that act by chemical means to lighten tooth color"-i.e. tooth whiteners.
Those ingredients are regularly contained in toothpaste and mouthwash products in low dose forms, and in higher-concentrated formulations meant to rapidly whiten teeth. While the lower-dose forms usually contain hydrogen peroxide or carbamide peroxide-ingredients which have obtained approval from FDA-other products, such as "extracoronal whitening and bleaching products," have not yet been classified by FDA as either a drug or cosmetic product.
As noted in the ADA's citizen petition, the latter products are not without risks to consumers. The products can cause damage to both a patient's teeth and "soft tissue" in the mouth, and are, "Easily over-used and abused by individuals who assume that the products are safe since they are readily available."
And while there's certainly an economic component to the ADA's argument-tighter regulation reinforces its argument that only dentists should apply tooth-whitening products, thereby protecting their profits-it's not an argument without merit. For example, the whitening products can "mask" visible signs that indicate professional medical treatment is necessary. Tooth color can be an indicator of these changes, the ADA wrote.
However, ADA's petition was opposed by some companies, such as Proctor & Gamble, which argued that whitening products, such as its widely used Crest Whitestrips, are generally safe and "correctly classified as cosmetic products"-not drugs or medical devices.
The petition also came nearly two decades after FDA was sued by Rembrandt after it sent the company a Warning Letter in 1991 alleging that one of its bleaching tooth whitener products, Rembrandt Gel, was in fact a drug and not a cosmetic under the Federal Food, Drug and Cosmetic Act (FD&C Act). While the lawsuit was later dropped after FDA agreed to re-review the product based on new information, the issue was never settled.
In Brief: What's a Drug, and What's a Cosmetic?
The FD&C Act defines a drug as:
(A) articles recognized in the official United States Pharmacopoeia, official Homoeopathic Pharmacopoeia of the United States, or official National Formulary, or any supplement to any of them; and
(B) articles intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease in man or other animals; and
(C) articles (other than food) intended to affect the structure or any function of the body of man or other animals; and (D) articles intended for use as a component of any article specified in clause (A), (B), or (C). A food or dietary supplement for which a claim, subject to sections 403(r)(1)(B) and 403(r)(3) or sections 403(r)(1)(B) and 403(r)(5)(D), is made in accordance with the requirements of section 403(r) is not a drug solely because the label or the labeling contains such a claim. A food, dietary ingredient, or dietary supplement for which a truthful and not misleading statement is made in accordance with section 403(r)(6) is not a drug under clause (C) solely because the label or the labeling contains such a statement.
Meanwhile, a cosmetic is defined under the same law as:
(1) articles intended to be rubbed, poured, sprinkled, or sprayed on, introduced into, or otherwise applied to the human body or any part thereof for cleansing, beautifying, promoting attractiveness, or altering the appearance, and
(2) articles intended for use as a component of any such articles; except that such term shall not include soap.
FDA has long held that whether a product is defined as a drug or something else is largely contingent upon the claims affixed to its label. For example, while a makeup product is usually a cosmetic, if its labeling also states that it treats a skin condition (e.g. acne), it would be regulated as a drug.
So what does FDA think-are tooth whiteners a cosmetic or a drug?
In a 22 April 2014 response to ADA's citizen petition-more than five years after it was first filed-FDA said the answer still isn't clear.
"The statutory definitions for drug and cosmetic are not mutually exclusive," FDA explained in its response. Some, as noted earlier, can be both a cosmetic and a drug, while others are just a cosmetic product or just a drug product.
And based on the general application of teeth-whitening products to whiten teeth rather than cure or treat a condition or disease, FDA said the "most hydrogen peroxide-containing tooth whiteners would meet the definition of cosmetic" under the FD&C Act.
But even FDA conceded that it still has unanswered questions about the safety and efficacy of the products. "The exact mechanism of peroxide-containing tooth whitening is not well-understood, making it difficult to determine whether the various formulations contained in the marketed products affect the structure or function of the body," FDA wrote, referring to clause (C) of the definition of "drug" in the FD&C Act. There is "insufficient data" to determine, one way or the other, if the whitening preparations "meet the definition of a drug," FDA continued, citing the differences between surface stains and deep intrinsic stains.
Further, FDA said it has "insufficient data" to determine if the products posed safety risks to human health on a class-wide basis, especially given their range of concentrations and formulations and various labeled indications.
Ultimately, FDA said it would continue to regulate teeth-whitening products on a case-by-case basis, eschewing the class-wide regulatory scheme sought by the ADA and keeping in place the regulatory regime of the status quo.