Written By: Pharmacally Medical News Desk
Polyrizon Ltd. has submitted a Pre-Request for Designation (Pre-RFD) to the U.S. Food and Drug Administration for PL-16, its investigational Viral Blocker nasal spray. The submission is intended to initiate regulatory dialogue to identify the appropriate classification and development pathway for the product.
PL-16 is described as a non-pharmacological intranasal product designed to reduce exposure to airborne respiratory viruses, including influenza and common cold viruses. The product forms a temporary physical barrier on the nasal mucosa to limit the ability of inhaled viral particles to reach the nasal epithelium.
Polyrizon said PL-16 is based on a hydrogel platform that creates a thin coating after application. The hydrogel consists of biodegradable polymers and commonly used excipients and is administered as a metered-dose intranasal spray. The company stated that the product is intended for local topical action only and does not rely on pharmacological, immunological, or metabolic activity.
According to Polyrizon, in-vitro studies demonstrated that PL-16 preserved cell viability when cells were exposed to influenza A (H1N1) and human coronavirus 229E. The company reported that the technology prevented viral access to the cells and that recovered virus remained infective, supporting a mechanical barrier mechanism rather than virucidal activity.
Polyrizon highlighted that PL-16 is part of a broader strategy to develop non-medicated intranasal solutions aimed at reducing exposure to airborne particles through physical barrier mechanisms. This strategy utilizes the company’s Capture and Contain (C&C) technology platform and includes PL-14 Allergy Blocker, which is designed to reduce exposure to airborne allergens using a similar locally acting, non-pharmacological approach.
Polyrizon also pointed to the ongoing burden of seasonal respiratory infections and referenced current U.S. estimates highlighting the impact of influenza on illness, healthcare use, and mortality.
Following feedback from the FDA on the Pre-RFD submission, Polyrizon plans to work with the agency to determine the next steps in the development of PL-16.
Reference
Polyrizon Submits Pre-Request for Designation to FDA for PL-16 Viral Blocker Designed to Reduce the Exposure to Influenza and Cold Viruses, GlobeNewswire, 19 December 2025, https://www.globenewswire.com/news-release/2025/12/19/3208473/0/en/Polyrizon-Submits-Pre-Request-for-Designation-to-FDA-for-PL-16-Viral-Blocker-Designed-to-Reduce-the-Exposure-to-Influenza-and-Cold-Viruses.html