Iodine revisited

Abstract

Iodine is an antiseptic that has been used in wound care for more than 150 years. Traditional formulations of iodine had serious limitations that were reduced in later products. Much has been written about iodine and opinions on its clinical efficacy are divided. There have been reviews of the chemical properties of iodine, its antimicrobial activity, human physiology, cytotoxicity and its clinical effectiveness, but few have addressed all these aspects. With the recent development of iodine-containing wound care products and the continued publication of laboratory and clinical studies, it seems timely to reassess the evidence relating to the effectiveness of iodine for treating wounds. This literature review attempts to provide an appropriate chemical and physiological background of the characteristics of iodine in order to provide a sound basis for understanding the available microbiological and clinical data. It will show that understanding the factors that contribute to the activity and potential cytotoxicity of iodine are important in evaluating the clinical evidence. Although definitive studies are needed, the sustained delivery of low doses of free iodine offers the potential to inhibit a broad range of microbial species without selecting for resistant strains or inducing cytotoxic effects.

Zebrafish Embryo Disinfection with Povidone–Iodine: Evaluating an Alternative to Chlorine Bleach

“…This could be attributed to the amount of available bactericidal iodine (e.g., hydrated iodine [I 2 ], hypoiodous acid [HOI], and iodine cation [H 2 OI + ]), as there are several potential reactions of molecular iodine in water (e.g., hydrolysis, dissociation, protonation, complex formation, and disproportionation) that could limit availability over time as more reactions are able to occur. 22 Shorter durations of PVPI exposures had less of an impact on embryo health as embryo mortality was increased significantly for 6 hpf embryo treatment with unbuffered 50 ppm-5 min compared to 50 ppm-2 min as well as 24 hpf embryo treatment of 25 ppm-2 min compared to 25 ppm-5 min. An exception to this pattern was with 24 hpf embryos treated with unbuffered 25 ppm PVPI for 2 min.…”

A Comprehensive Review of Topical Odor-Controlling Treatment Options for Chronic Wounds

“…60 , 61 Iodine is an antiseptic rather than an antimicrobial; despite more than 100 years of intensive use of iodine, its eff ectiveness against a variety of bacterial species has not diminished. 62 Despite its actions against a wide variety of pathogenic microorganisms, iodine can be cytotoxic. Since 1950, iodine has been manufactured as an iodophor (combination of iodine and a surfactant) to reduce its toxicity toward human cells.…”

A novel enzyme-based antimicrobial system comprising iodide and a multicopper oxidase isolated from Alphaproteobacterium strain Q-1

“…In aqueous solution, iodine has more than 10 chemical species including iodide ion (I -), molecular iodine (I 2 ), triiodide ion (I 3 -), hypoiodous acid (HOI), hypoiodite (OI -), and iodate (IO 3 -) (Gottardi 1983). Among these, I 2 is considered primarily responsible for the antimicrobial efficacy (Gottardi 1983;Cooper 2007). Although the exact mode of action of iodine is still unclear, it may rapidly penetrate the cell wall of microorganisms and oxidize the sulfhydryl groups of various proteins to form disulfide bridges (Gottardi 1983).…”

“…Iodine has a broad antimicrobial spectrum against a wide variety of microorganisms including bacteria, fungi, yeasts, viruses, and protozoa, and it has been used in the treatment of wounds as an iodine tincture for more than 170 years (Gottardi 1983;Cooper 2007). In aqueous solution, iodine has more than 10 chemical species including iodide ion (I -), molecular iodine (I 2 ), triiodide ion (I 3 -), hypoiodous acid (HOI), hypoiodite (OI -), and iodate (IO 3 -) (Gottardi 1983).…”

“…Povidone-iodine (PVP-I), one of the iodophors, is a stable complex of polyvinylpyrrolidone and elemental iodine and is widely used as a broad-spectrum antiseptic (Gottardi 1983;Cooper 2007). PVP-I contains two types of I 2 : complexed and non-complexed I 2 ; the latter is considered responsible for the antimicrobial activity of PVP-I and is designated Bfree iodine.^However, PVP-I is not eco-friendly since it contains surfactant and polyvinylpyrrolidone, and consequently, is difficult to use as an environmental disinfectant in food industries.…”