US-based clinical-stage biopharmaceutical company NRx Pharmaceuticals Inc (Nasdaq:NRXP) announced on Thursday the transmission of its Abbreviated New Drug Application (ANDA) for electronic filing to the US Food and Drug Administration (FDA) for NRX-100, its preservative-free IV ketamine formulation, for use in all existing approved indications such as anaesthesia and pain management.

The company says that it anticipates filing a citizen's petition with the FDA to remove benzethonium chloride, a known neurotoxic and cytotoxic substance, from presentations of ketamine intended for intravenous use. Its management believes that the preservative-free feature of NRX-100 will be deemed of benefit to patients because of the known toxicity of closely related benzalkonium chloride in current drug products. Should the citizen's petition be granted, all formulations of ketamine sold in the US could face a regulatory requirement to be free of preservatives.

This latest filing supplements the New Drug Application currently being completed by the company to extend the labelled indications of ketamine to include the treatment of suicidal depression. The company says that it anticipates submitting clinical trials data from more than 1,000 patients and real-world data from more than 180,000 patients in which ketamine demonstrated superiority to placebo and active placebo, with noninferiority to electroconvulsive therapy.