NRx Pharmaceuticals announced that the FDA Office of Generic Drugs has determined that the company’s preservative-free ketamine formulation has no identified bioequivalence deficiencies. The determination is deemed preliminary until final supervisory review of NRx’s Abbreviated New Drug Application (ANDA), with anticipated FDA approval in Summer 2026. This is significant because NRx’s proposed product is the first ketamine formulation free of benzethonium chloride (BZT), a known toxic preservative that is not listed by the FDA as Generally Recognized as Safe (GRAS) and is no longer permitted in certain topical consumer applications. Ketamine formulations containing BZT date back to an era when the safety profile of quaternary amine preservatives was less well characterized.
Manufacturing and Supply Chain Focus
Prior to NRx’s preservative-free formulation, it was widely believed that BZT was required to maintain room temperature stability and sterility of ketamine. NRx anticipates demonstrating three years of room temperature stability and sterility for its preservative-free product. The company has filed patents in the U.S. and internationally to support its preservative-free formulation and has the potential to create a “branded generic” product. NRx’s preservative-free product is manufactured in the United States at a time when the FDA has identified ketamine as strategically important and emphasized the need for resilient domestic supply chains. The FDA recently awarded a Commissioner’s National Priority Voucher to support the establishment of a new U.S. manufacturing source of ketamine drug substance, reflecting regulatory focus on reshoring essential medicines and reducing reliance on foreign supply.
Parallel Regulatory Pathways
The ANDA process is separate from NRx’s path to a New Drug Application to use ketamine in treating depression. NRX-100, preservative-free intravenous ketamine, has been awarded Fast Track Designation for treating suicidal ideation in depression, including bipolar depression. NRX-101, an oral D-cycloserine and lurasidone combination, has been awarded Breakthrough Therapy Designation for treating suicidal bipolar depression. NRx is preparing a New Drug Application under Fast Track Designation to expand the use of intravenous ketamine for patients with severe depression who may have suicidal ideation, separate from its ANDA filing.
This article is an AI-assisted summary. All facts and figures are drawn from the original report: https://www.globenewswire.com/news-release/2026/03/17/3257011/0/en/NRx-Pharmaceuticals-Nasdaq-NRXP-Announces-FDA-Bioequivalence-Determination-by-Office-of-Generic-Drugs-for-NRx-s-Preservative-Free-Ketamine-Application.html