Citizen Petition to Declare Pyridoxamine Not Excluded from the Dietary Supplement Definition

By Riëtte van Laack

I understand if this title made you think for a minute, did I read that right? You probably did. Another Citizen Petition regarding pyridoxamine was filed. This one asks that FDA essentially undo what it did in 2009.

Pyridoxamine is a form of vitamin B6. In July 1999, BioStratum Inc., a pharmaceutical company, filed an IND with FDA to study pyridoxamine's potential use as a drug for diabetic nephropathy. In 2005, Biostratum Inc. filed a citizen petition asking that FDA stop the marketing of pyridoxamine as a dietary supplement, pursuant to section 201(ff)(3)(B) of the Federal Food, Drug, and Cosmetic Act, which excludes from the dietary supplement definition an ingredient that was subject to substantial clinical investigations and the existence of these clinical investigations had been made public before the ingredient was first marketed as a dietary supplement or food. In 2009, FDA agreed, concluding that there was no evidence that pyridoxamine was marketed as a food or dietary supplement before the IND was filed. Thus, the marketing of pyridoxamine as dietary supplement was illegal as the substance was excluded from the dietary supplement definition under FDC Act § 201(ff)(3)(B) (see our previous post here).

Eight years later, the INDs for pyridoxamine were withdrawn and a new joint venture, Vi Guard Health Inc. (Petitioner), now wants to market an oral formulation of pyridoxamine as a dietary supplement. In order to do so, action by FDA is required. Last week, Vi Guard Health Inc. submitted a citizen petition requesting that the Agency declare or issue a regulation that pyridoxamine is not excluded from the definition of, and may legally be marketed as, a dietary supplement.

Petitioner requests that FDA issue either a regulation declaring that pyridoxamine is no longer excluded from the definition of dietary supplement or a regulation authorizing that pyridoxamine may be marketed as a dietary supplement even though it was subject to clinical investigations prior to the first marketing of the substance as a food or dietary supplement.

The FDC Act, as amended by the Dietary Supplement Health and Education Act (“DSHEA”) of 1994, excludes from the definition of dietary supplement any article that is approved as a new drug and any article “authorized for investigation as a new drug . . . for which substantial clinical investigations have been instituted and for which the existence of such investigations have been made public” unless the article was “before such approval, . . . or authorization marketed as a dietary supplement or as a food.” FDC Act § 201(ff)(3)(B). FDA has the authority to over-ride the exclusion by regulation.

The exclusionary clause provision is intended to protect investments by pharmaceutical companies; it prevents the marketing of a substance as a dietary supplement when these products are being developed into drugs. Petitioner claims that in the case of pyridoxamine, “the pharmaceutical industry’s interests are no longer at stake.” All clinical investigations on pyridoxamine have ceased and, according to Petitioner and available evidence, there is no drug industry interest in resuming them. In addition, because pyridoxamine has various beneficial effects that other forms of vitamin B6 may not have, “[g]ranting [the requested] exception would give consumers access to a beneficial article.”

To our knowledge, this is the second time FDA has been asked to issue a regulation authorizing the marketing of a substance as a dietary supplement even though the substance was the subject of an IND before it was marketed as a food or dietary supplement. A 2009 Petition by OVOS Natural Health, Inc. to allow the marketing of homotaurine as a dietary supplement was the first (see our previous post here). FDA denied that Petition because, according to FDA, homotaurine was not a dietary ingredient. FDA never reached the issue of its authority under FDC Act § 201(ff)(3)(B). Since pyridoxamine is a member of the vitamin B6 family, and thus falls well within the definition of a dietary ingredient under FDC Act § 201(ff)(l )(A), FDA cannot punt on that issue this time.