Polyrizon Ltd., a pre-clinical-stage biotechnology company, has submitted a Pre-Request for Designation (Pre-RFD) to the U.S. Food and Drug Administration (FDA) for its PL-16 Viral Blocker. This non-pharmacological intranasal product is designed to reduce exposure to airborne respiratory viruses, such as influenza and cold viruses, by forming a temporary physical barrier on the nasal mucosa. The Pre-RFD submission initiates a formal regulatory dialogue with the FDA to determine the appropriate regulatory pathway for PL-16 based on its physical mode of action.