NRx files Citizen Petition with FDA seeking removal of BZT from ketamine

NRx Pharmaceuticals (NRXP) announced the filing of a Citizen Petition with the FDA seeking the removal of Benzethonium Chloride from all forms of ketamine sold in the United States. Benzethonium Chloride, or BZT, is a preservative with known toxicity that is not Generally Recognized as Safe, or GRAS, by the FDA for parenteral products and not Generally Recognized as Safe and Effective, or GRASE, for topical products. It belongs to a class of quaternary amine preservatives that is known to be toxic to epithelial cells and to demonstrate neurotoxicity. This class of preservatives has been removed from many eyedrops because of demonstrated toxicity to the conjunctiva and corneal nerves. The FDA no longer allows BZT to be used in hand cleansers and topical antiseptics. In June 2025 NRx filed an Abbreviated New Drug Application with the FDA for a preservative-free preparation of ketamine, demonstrating support for 3 year room temperature stability and sterility. NRx has similarly filed a patent on its preservative-free process, in light of prior art that suggested BZT was required for long term stability and sterility.