Iodine-based formulations have been widely used by a number of markets both as antiseptics and disinfectants. It was first used for the treatment of wounds about 140 years ago. An iodophor is a mixture of iodine and a solubilizing agent or carrier which produces a solution that provides a sustained-release reservoir of iodine and releases small amounts of free iodine in aqueous solution. Iodine solutions or tinctures have been used primarily as antiseptics on skin or tissue. The best-known and most widely used iodophor is povidone-iodine, a compound of polyvinylpyrrolidone with iodine. This product and other iodophors retain the germicidal efficacy of iodine but unlike iodine generally are non-staining and relatively free of toxicity and irritancy.
Iodine imposes broad spectrum antimicrobial activity due to its ability to penetrate the cell wall of microorganisms which results in disruption of protein and nucleic acid structure and synthesis. Povidone-Iodine prevents viruses from anchoring to host cells by incorporating the free iodine to the viral capsid surface. In bacteria, povidone-iodine releases the iodine ion to react with membrane proteins’ amino acid side chains and thus disrupt cellular vitality. Published reports demonstrate that iodophors are bactericidal, mycobactericidal, and virucidal but can require prolonged contact times to kill certain fungi and bacterial spores.
Mutagenic properties of Iodophors have been identified against bacterial and yeast cells; however not tested on human tissue. Allergic reaction (and in some cases anaphylactic shock) to iodine appear in several cases of diagnostics upon use of povidone-iodine. From an environmental perspective, aquatic concentrations of povidone-iodine and/or its degraded by-products are considered toxic to certain aquatic creatures.
Here’s how we would score Iodophors on the key decision making criteria:
• Speed of Disinfection – B
o Contact times will be dependent upon concentration and formulation
o Hand Sanitizing formulations generally carry a 30 second sanitizing claims
• Spectrum of Kill – B to C
o Efficacy against bacteria, viruses and fungi has been shown but is dependent upon formulation and concentration
• Cleaning Effectiveness – C to D
o Iodine itself widely stains surfaces
o Any cleaning efficacy that may be present in Iodophors solutions would be as a result of surfactants included in the formulation
• Safety Profile – B
o Allergic reactions to iodine have been well documented
o Mutagenic properties of Iodophors have been identified against bacterial and yeast cells; but not verified on human tissue
• Environmental Profile – D
o Povidone-iodine and/or its degraded by-products are considered toxic to certain aquatic creatures
• Cost Effectiveness – B to C
o Products are available from a number of suppliers
**For more in-depth scientific information about Alcohol and other disinfectant chemistries, stay tuned to www.infectionpreventionresource.com.