New research published in ACS Omega reveals that traditional iodine antiseptics deliver miniscule quantities of free molecular iodine, the only biocidal agent in such products, and points to techniques to close the reliability gap.

ASHBURN, Va.--(BUSINESS WIRE)--November 12, 2026--

I2Pure Corp., an iodine technology company advancing free molecular iodine (I₂) research and technology for health and biosafety applications, today announced the recent publication of a new peer-reviewed study led by its senior scientists, Ilker S. Bayer, Ph.D., and Jack Kessler, Ph.D., in ACS Omega, a journal of the American Chemical Society. View profile information about Drs. Bayer and Kessler (https://i2pure.com/PR-I2Pure-Peer-Reviewed-Study-PPM-Gap.shtml) here.

The study, "Transport of Molecular Iodine from Antiseptic Iodophors across Hydrophilic–Lipophilic Interfaces: Influence of Phospholipids," reveals empirical evidence on a question with direct clinical relevance: how much free I₂ in a povidone-iodine (PVP-I) antiseptic is actually available to fight pathogens, and what can be done to maximize its availability.

“Healthcare has long relied on a single indicator of iodophor strength — titratable iodine — to describe antiseptic capability," said Dr. Bayer, lead author of the study and Chief Scientist at I2Pure. "But that number doesn’t tell you how much free molecular iodine, the actual active antimicrobial agent, is unbound and available to provide antiseptic efficacy. Our data puts hard numbers behind that gap for the first time and reveals that traditional PVP-I formulations deliver miniscule levels of free molecular iodine. The balance of the iodine is so chemically bound to its carrier that it is not available to serve any antimicrobial purpose."

Key Findings

Using a heptane-water interface model designed to mimic biological hydrophilic-lipophilic conditions, the research team tested five commercial PVP-I formulations and one dextrin-iodine complex, each standardized to 1% titratable iodine. Among the findings:

  • At full strength, standard PVP-I formulations released only about 4% of their titratable iodine across the interface — consistent with prior literature indicating that more than 99% of the iodine in PVP-I remains chemically bound and unavailable.
  • Diluting PVP-I solutions 8- to 10-fold temporarily increases the release of free I₂.
  • The dextrin-iodine (cadexomer-iodine) complex tested consistently outperformed the PVP-I formulations, achieving more rapid and incremental iodine release across nearly every condition studied.
  • The presence of phospholipids — representative of components found in biological membranes and bacterial cell walls — enhanced iodine transport, confirming the strong lipophilicity of molecular iodine and suggesting a charge-transfer interaction between free I₂ and lipids that may help explain its antimicrobial mechanism at the cellular level even when only small quantities of free I₂ are available.
  • Release kinetics were successfully modeled using Weibull and Michaelis-Menten mathematical frameworks (R² > 0.988), giving researchers a quantitative basis for comparing and optimizing iodophor formulations going forward.

"What stood out to me is how consistent the pattern was across different formulations and conditions," said Dr. Kessler, co-author and Chief Scientific Officer at I2Pure. "Carrier chemistry and dilution ratio aren’t minor formulation details — they’re the difference between an antiseptic that delivers meaningful free iodine and one that mostly holds onto it. That has real implications for how these products are used in clinical settings."

Why It Matters

Healthcare providers rely on iodine formulations for myriad applications, from topical antisepsis to surgery preparation to intraoperative rinses. If “titratable iodine” is an unreliable indicator of iodophor strength, many healthcare providers may be using these formulations based upon false confidence, resulting in a reliability gap. Because free I₂ — not bound or complexed iodine — is the active biocide in these products, understanding the gap between titratable and free I₂ has implications for antiseptic formulation, clinical dilution protocols, and infection-control practice across healthcare, including but not limited to topical, surgical, and wound-care settings. Future iodophor products will benefit from a structure that maximizes the availability of free I₂, closing the reliability gap that may exist in the use of PVP-I or other complexed iodine products.

The ACS Omega publication is the latest in a series of recent peer-reviewed publications from I2Pure's science team. Previous publications include a University of California San Diego study confirming the antimicrobial performance of I2Pure's molecular iodine formulations against multidrug-resistant pathogens (published in Antimicrobial Agents and Chemotherapy) and a comprehensive review of cellulose-based drug delivery systems authored by Dr. Bayer (published in Polymers). For a full list of I2Pure publications, please visit i2pure.com.

About I2Pure

I2Pure is an iodine technology company dedicated to advancing health and biosafety through its patented, non-toxic molecular iodine solutions. I2Pure's mission is to prevent pathogenic threats to the world. Its proprietary technology platform has potential applications across healthcare, industrial biosafety, consumer products, and food processing and can be delivered directly or through carriers in solutions, nanoparticles, polymers, and coatings.

View the I2Pure website for more information or contact the company at info@i2pure.com.

info@i2pure.com