Povidone-Iodine (PVP-Iodine)

Chemical structure
Iodine is a non-metallic element (atomic number 53 in the periodic table) in the group of halogens. The name derives from the Greek word ‘ioeides’ = violet-like, and refers to the development of violet vapors when heated. In 1812, the French chemist Bernard Courtois (1777-1838) for the first time extracted iodine as element from the ashes of seaweed.

Chemical structure of the Polyvinylpyrrolidon-Iodine complex (PVP-Iod):

Characteristics
Iodine, not only being an important micro element for human beings, is also used for antisepsis due to its comprehensive antimicrobial characteristics. Compared to the formerly used pure iodine tincture, the modern PVP-Iodine complex, a so-called iodophore, possesses significantly better efficacy and compatibility. In aqueous solutions, the PVP-Iodine complex acts like an iodine depot. Only approximately one thousandth part of the total iodine is freely available for the microbiocidal activity. The bigger part is bound as so-called available iodine and constitutes a reservoir for supplying active iodine. In case the chemical balance is shifted – i.e. free iodine is needed for disinfection purposes – additional iodine is released. PVP-Iodine (1.0 – 1.3 % as free iodine) has a rapid and comprehensive effect against bacteria, mycobacteria, antibiotic-resistant bacteria, yeast fungi and dermatophytes. The onset of effect against mold fungi and bacterial spores is slower. So far, there are no reports in the literature which indicate that microorganisms develop resistances against PVP-Iodine.

Effect mechanisms
Also with low concentrations, the onset of effect takes place very quickly. Molecular iodine is able to penetrate microorganisms and to react with cellular parts. Due to the highly oxidative activity, molecular iodine rapidly reacts with free hydroxyl groups (-OH) and free mercaptan groups (-SH) of amino acids and unsaturated fatty acids. This results in a destruction of the structure and the related functions of proteins and other cell components. These reactions with the cellular components of microorganisms finally result in the microorganisms’ death.

Fields of application
Ready-to-use, standardized PVP-Iodine solutions are predominantly used for antisepsis of skin and mucous membranes, for preoperative antisepsis and for wound irrigations. PVP-Iodine preparations can be directly applied to small and larger wounds as well as to the surrounding dermal tissue.
PVP-Iodine may not be used on patients suffering from hyperthyroidism and other existing thyroid diseases.