Antiseptics can be subdivided into about eight classes of materials. These classes can be subdivided according to their mechanism of action: small molecules that indiscriminately react with organic compounds and kill microorganisms (peroxides, iodine, phenols) and more complex molecules that disrupt the cell walls of the bacteria. •
Alcohols, including
ethanol and 2-propanol/
isopropanol are sometimes referred to as
surgical spirit. They are used to disinfect the skin before injections, among other uses. •
Diguanides including
chlorhexidine gluconate, a bacteriocidal antiseptic which (with an alcoholic solvent) is considered a safe and effective antiseptic for reducing the risk of infection after clean surgery, including tourniquet-controlled upper limb surgery. It is also used in mouthwashes to treat inflammation of the gums (
gingivitis).
Polyhexanide (polyhexamethylene biguanide, PHMB) is an antimicrobial compound suitable for clinical use in critically colonized or infected acute and chronic wounds. The physicochemical action on the bacterial envelope prevents or impedes the development of resistant bacterial strains. •
Iodine, especially in the form of
povidone-iodine, is widely used because it is well tolerated; does not negatively affect wound healing; leaves a deposit of active iodine, thereby creating the so-called "remnant", or persistent effect; and has wide scope of antimicrobial activity. The traditional iodine antiseptic is an
alcohol solution (called
tincture of iodine) or as
Lugol's iodine solution. Some studies do not recommend disinfecting minor wounds with iodine because of concern that it may induce scar tissue formation and increase healing time. However, concentrations of 1% iodine or less have not been shown to increase healing time and are not otherwise distinguishable from treatment with saline. Iodine will kill all principal pathogens and, given enough time, even
spores, which are considered to be the most difficult form of microorganisms to be inactivated by disinfectants and antiseptics. •
Octenidine dihydrochloride, currently increasingly used in continental Europe, often as a chlorhexidine substitute. •
Peroxides, such as
hydrogen peroxide and
benzoyl peroxide. Commonly, 3% solutions of hydrogen peroxide have been used in household first aid for scrapes, etc. However, the strong oxidization causes scar formation and increases healing time during fetal development. •
Phenols such as phenol itself (as introduced by Lister) and
triclosan,
hexachlorophene,
chlorocresol, and
chloroxylenol. The fact that the more substituted and more
lipophylic phenols are less toxic, less irritant and more powerful was gradually discovered in late 19th century. Nowadays comparatively more water-soluble phenols such as chlorocresol are commonly used as preservatives in personal care products while less soluble such as chloroxylenol – as topical antiseptics. Both can be encountered in household disinfectants. •
Quat salts such as
benzalkonium chloride/lidocaine (trade name Bactine among others),
cetylpyridinium chloride, or
cetrimide. These surfactants disrupt cell walls. •
Quinolines such as hydroxyquinolone, dequalium chloride, or
chlorquinaldol. •
4-Hexylresorcinol, or S.T.37 ==See also==