Betadine
Encyclopedia
Povidone-iodine is a stable chemical complex
of polyvinylpyrrolidone (povidone, PVP) and elemental iodine
. It contains from 9.0% to 12.0% available iodine, calculated on a dry basis
.
This unique complex was discovered at the Industrial Toxicology Laboratories in Philadelphia by H. A. Shelanski and M. V. Shelanski. They carried out tests in vitro to demonstrate anti-bacterial activity, and found that the complex was less toxic than tincture of iodine
in mice. Human clinical trials showed the product to be superior to other iodine formulations.
It was first sold in 1955, and has since become the universally preferred iodine antiseptic.
, polyethylene glycol
, and glycerol
. Its stability in solution is much greater than that of tincture of iodine or Lugol's solution.
Free iodine, slowly liberated from the poviodine-iodine (PVP-I) complex in solution, kills eukaryotic or prokaryotic cells through iodination of lipids and oxidation of cytoplasmic and membrane compounds. This agent exhibits a broad range of microbicidal activity against bacteria
, fungi, protozoa
, and viruses. Slow release of iodine from the PVPI complex in solution minimizes iodine toxicity towards mammalian cells.
Following the discovery of iodine by Bernard Courtois
in 1811, it has been broadly used for the prevention and treatment of skin infections, and the treatment of wounds. Iodine has been recognized as an effective broad-spectrum bactericide, and it is also effective against yeasts, molds, fungi, viruses, and protozoans. Drawbacks to its use in the form of aqueous solutions include irritation at the site of application, toxicity and the staining of surrounding tissues. These deficiencies were overcome by the discovery and use of PVP-I, in which the iodine is carried in a complexed form and the concentration of free iodine is very low. The product thus serves as an iodophor
.
In addition, it has been demonstrated that bacteria do not develop resistance to PVP-I, and the sensitization rate to the product is only 0.7%
Consequently, PVP-I has found broad application in medicine as a surgical scrub; for pre- and post-operative skin cleansing; for the treatment and prevention of infections in wounds, ulcers, cuts and burns; for the treatment of infections in decubitus ulcers and stasis ulcers; in gynecology for vaginitis
associated with candidal
, trichomonal or mixed infections. For these purposes PVP-I has been formulated at concentrations of 7.5–10.0% in solution, spray, surgical scrub, ointment, and swab dosage forms. It is available without a prescription under the generic name povidone-iodine or the brand name Betadine
.
It is used in pleurodesis
(fusion of the pleura because of incessant pleural effusions). For this purpose, povidone-iodine is equally effective and safe as talc
, and may be preferred because of easy availability and low cost.
2.5% buffered
PVP-I solution
can be used for prophylaxis of neonatal conjunctivitis (Ophthalmia neonatorum) which can lead to blindness
, especially if it is caused by Neisseria gonorrhoeae
, or Chlamydia trachomatis
. PVP-I appears to be very suitable for this purpose because unlike other substances it is efficient also against fungi and virus
es (including HIV
and Herpes simplex
).
PVP-I can be loaded into hydrogels (based on carboxymethyl cellulose
, poly(vinyl alcohol)
and gelatin
, or on crosslinked polyacrylamide
). These hydrogels can be used for wound
dressing. The rate of release of the iodine in the PVP-I is heavily dependent on the hydrogel composition. The release rate increases with more CMC/PVA and decreases with more gelatin.
Complex (chemistry)
In chemistry, a coordination complex or metal complex, is an atom or ion , bonded to a surrounding array of molecules or anions, that are in turn known as ligands or complexing agents...
of polyvinylpyrrolidone (povidone, PVP) and elemental iodine
Iodine
Iodine is a chemical element with the symbol I and atomic number 53. The name is pronounced , , or . The name is from the , meaning violet or purple, due to the color of elemental iodine vapor....
. It contains from 9.0% to 12.0% available iodine, calculated on a dry basis
Dry basis
Dry basis is a expression of the calculation in chemistry, chemical engineering and related subjects, in which the presence of water is ignored for the purposes of the calculation...
.
This unique complex was discovered at the Industrial Toxicology Laboratories in Philadelphia by H. A. Shelanski and M. V. Shelanski. They carried out tests in vitro to demonstrate anti-bacterial activity, and found that the complex was less toxic than tincture of iodine
Tincture of iodine
Tincture of iodine is a disinfectant, usually 2–7% elemental iodine, along with potassium iodide or sodium iodide, dissolved in a mixture of ethanol and water. As in the case of Lugol's iodine, the role of iodide and water in the solution is to increase the solubility of the elemental iodine, by...
in mice. Human clinical trials showed the product to be superior to other iodine formulations.
It was first sold in 1955, and has since become the universally preferred iodine antiseptic.
Properties
PVP-I is completely soluble in cold water, ethyl alcohol, isopropyl alcoholIsopropyl alcohol
Isopropyl alcohol is a common name for a chemical compound with the molecular formula C3H8O. It is a colorless, flammable chemical compound with a strong odor...
, polyethylene glycol
Polyethylene glycol
Polyethylene glycol is a polyether compound with many applications from industrial manufacturing to medicine. It has also been known as polyethylene oxide or polyoxyethylene , depending on its molecular weight, and under the tradename Carbowax.-Available forms:PEG, PEO, or POE refers to an...
, and glycerol
Glycerol
Glycerol is a simple polyol compound. It is a colorless, odorless, viscous liquid that is widely used in pharmaceutical formulations. Glycerol has three hydroxyl groups that are responsible for its solubility in water and its hygroscopic nature. The glycerol backbone is central to all lipids...
. Its stability in solution is much greater than that of tincture of iodine or Lugol's solution.
Free iodine, slowly liberated from the poviodine-iodine (PVP-I) complex in solution, kills eukaryotic or prokaryotic cells through iodination of lipids and oxidation of cytoplasmic and membrane compounds. This agent exhibits a broad range of microbicidal activity against bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
, fungi, protozoa
Protozoa
Protozoa are a diverse group of single-cells eukaryotic organisms, many of which are motile. Throughout history, protozoa have been defined as single-cell protists with animal-like behavior, e.g., movement...
, and viruses. Slow release of iodine from the PVPI complex in solution minimizes iodine toxicity towards mammalian cells.
Uses
Bernard Courtois
Bernard Courtois, also spelled Barnard Courtois, was a French chemist born in Dijon, France.- Early life :...
in 1811, it has been broadly used for the prevention and treatment of skin infections, and the treatment of wounds. Iodine has been recognized as an effective broad-spectrum bactericide, and it is also effective against yeasts, molds, fungi, viruses, and protozoans. Drawbacks to its use in the form of aqueous solutions include irritation at the site of application, toxicity and the staining of surrounding tissues. These deficiencies were overcome by the discovery and use of PVP-I, in which the iodine is carried in a complexed form and the concentration of free iodine is very low. The product thus serves as an iodophor
Iodophor
An Iodophor is a preparation containing iodine complexed with a solubilizing agent, such as a surfactant or povidone . The result is a water-soluble material that releases free iodine when in solution...
.
In addition, it has been demonstrated that bacteria do not develop resistance to PVP-I, and the sensitization rate to the product is only 0.7%
Consequently, PVP-I has found broad application in medicine as a surgical scrub; for pre- and post-operative skin cleansing; for the treatment and prevention of infections in wounds, ulcers, cuts and burns; for the treatment of infections in decubitus ulcers and stasis ulcers; in gynecology for vaginitis
Vaginitis
Vaginitis is an inflammation of the vagina. It can result in discharge, itching and pain, and is often associated with an irritation or infection of the vulva. It is usually due to infection. The three main kinds of vaginitis are bacterial vaginosis , vaginal candidiasis, and trichomoniasis. A...
associated with candidal
Candida
- Biology :* Candida , a genus of yeasts* Malvasia Candida, a variety of grape- Places :* Candida, Campania, a comune in the province of Avellino, Italy* Candida Casa, a church established by St Ninian at Whithorn, Dumfries and Galloway, Scotland...
, trichomonal or mixed infections. For these purposes PVP-I has been formulated at concentrations of 7.5–10.0% in solution, spray, surgical scrub, ointment, and swab dosage forms. It is available without a prescription under the generic name povidone-iodine or the brand name Betadine
Betadine
Povidone-iodine is a stable chemical complex of polyvinylpyrrolidone and elemental iodine. It contains from 9.0% to 12.0% available iodine, calculated on a dry basis....
.
It is used in pleurodesis
Pleurodesis
Pleurodesis is a medical procedure in which the pleural space is artificially obliterated. It involves the adhesion of the two pleura.- Uses :Pleurodesis is done to prevent recurrence of pneumothorax or recurrent pleural effusion...
(fusion of the pleura because of incessant pleural effusions). For this purpose, povidone-iodine is equally effective and safe as talc
Talc
Talc is a mineral composed of hydrated magnesium silicate with the chemical formula H2Mg34 or Mg3Si4O102. In loose form, it is the widely-used substance known as talcum powder. It occurs as foliated to fibrous masses, its crystals being so rare as to be almost unknown...
, and may be preferred because of easy availability and low cost.
2.5% buffered
Buffer solution
A buffer solution is an aqueous solution consisting of a mixture of a weak acid and its conjugate base or a weak base and its conjugate acid. It has the property that the pH of the solution changes very little when a small amount of strong acid or base is added to it. Buffer solutions are used as a...
PVP-I solution
Solution
In chemistry, a solution is a homogeneous mixture composed of only one phase. In such a mixture, a solute is dissolved in another substance, known as a solvent. The solvent does the dissolving.- Types of solutions :...
can be used for prophylaxis of neonatal conjunctivitis (Ophthalmia neonatorum) which can lead to blindness
Blindness
Blindness is the condition of lacking visual perception due to physiological or neurological factors.Various scales have been developed to describe the extent of vision loss and define blindness...
, especially if it is caused by Neisseria gonorrhoeae
Neisseria gonorrhoeae
Neisseria gonorrhoeae, also known as gonococci , or gonococcus , is a species of Gram-negative coffee bean-shaped diplococci bacteria responsible for the sexually transmitted infection gonorrhea.N...
, or Chlamydia trachomatis
Chlamydia trachomatis
Chlamydia trachomatis, an obligate intracellular human pathogen, is one of three bacterial species in the genus Chlamydia. C. trachomatis is a Gram-negative bacteria, therefore its cell wall components retain the counter-stain safranin and appear pink under a light microscope.The inclusion bodies...
. PVP-I appears to be very suitable for this purpose because unlike other substances it is efficient also against fungi and virus
Virus
A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...
es (including HIV
HIV
Human immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive...
and Herpes simplex
Herpes simplex
Herpes simplex is a viral disease caused by both Herpes simplex virus type 1 and type 2 . Infection with the herpes virus is categorized into one of several distinct disorders based on the site of infection. Oral herpes, the visible symptoms of which are colloquially called cold sores or fever...
).
PVP-I can be loaded into hydrogels (based on carboxymethyl cellulose
Carboxymethyl cellulose
Carboxymethyl cellulose or cellulose gum is a cellulose derivative with carboxymethyl groups bound to some of the hydroxyl groups of the glucopyranose monomers that make up the cellulose backbone...
, poly(vinyl alcohol)
Polyvinyl alcohol
Polyvinyl alcohol is a water-soluble synthetic polymer .-Properties:...
and gelatin
Gelatin
Gelatin is a translucent, colorless, brittle , flavorless solid substance, derived from the collagen inside animals' skin and bones. It is commonly used as a gelling agent in food, pharmaceuticals, photography, and cosmetic manufacturing. Substances containing gelatin or functioning in a similar...
, or on crosslinked polyacrylamide
Polyacrylamide
Polyacrylamide is a polymer formed from acrylamide subunits. It can be synthesized as a simple linear-chain structure or cross-linked, typically using N,N-methylenebisacrylamide. Polyacrylamide is not toxic...
). These hydrogels can be used for wound
Wound
A wound is a type of injury in which skin is torn, cut or punctured , or where blunt force trauma causes a contusion . In pathology, it specifically refers to a sharp injury which damages the dermis of the skin.-Open:...
dressing. The rate of release of the iodine in the PVP-I is heavily dependent on the hydrogel composition. The release rate increases with more CMC/PVA and decreases with more gelatin.
Alternative
In a clinical study of approximately 850 patients which compared the efficacy in preventing post-operative infection of pre-operative skin cleansing using chlorhexidine-alcohol vs. povidone-iodine, the rate of surgical-site infection was significantly lower in the chlorhexidine-alcohol group than in the povidone-iodine group (overall, 9.5% vs. 16.1%). Chlorhexidine-alcohol was significantly more protective than povidone-iodine against both superficial incisional infections (4.2% vs. 8.6%) and also deep incisional infections (1% vs. 3%). The incidence of organ-space infections was, however, not significantly different between the groups (4.4% vs. 4.5%). The team performing the study believes that, although both the antiseptic preparations possess broad-spectrum antimicrobial activity, the more effective protection provided by chlorhexidine-alcohol may be due to its more rapid action, its persistent activity (even when exposed to bodily fluids), and some residual effect.Nanomaterials
Recently povidone-iodine has found application in the field of nanomaterials. A wound-healing application has been developed which employs a mat of single wall carbon nanotubes (SWNTs) coated in a monolayer of povidone-iodine. It has been previously shown that the polymer polyvinylpyrrolidone (PVP, povidone) can coil around individual carbon nanotubes to make them water-soluble. This povidone-iodine coated carbon nanotube mat serves an electrically conductive bandage with antiseptics properties. Traditionally povidone-iodine is soaked into absorbent materials for application to wound sites, but this can lead to contact burns if excessive amounts of povidone-iodine are used. Additionally, traditional methods can allow large quantities of povidone-iodine to be released from the bandage material upon contact with fluids at the wound site. Meanwhile, the carbon nanotube supported povidone-iodine is prevented from escaping from the bandage in large amounts, and after an initial release of excess povidone-iodine to the wound site, a secondary slow release of iodine from the carbon nanotube bound povidone takes place.See also
- Tincture of iodineTincture of iodineTincture of iodine is a disinfectant, usually 2–7% elemental iodine, along with potassium iodide or sodium iodide, dissolved in a mixture of ethanol and water. As in the case of Lugol's iodine, the role of iodide and water in the solution is to increase the solubility of the elemental iodine, by...
- Lugol's iodineLugol's iodineLugol's iodine, also known as Lugol's solution, first made in 1829, is a solution of elemental iodine and potassium iodide in water, named after the French physician J.G.A. Lugol. Lugol's iodine solution is often used as an antiseptic and disinfectant, for emergency disinfection of drinking water,...
- BetadineBetadinePovidone-iodine is a stable chemical complex of polyvinylpyrrolidone and elemental iodine. It contains from 9.0% to 12.0% available iodine, calculated on a dry basis....
- IodophorIodophorAn Iodophor is a preparation containing iodine complexed with a solubilizing agent, such as a surfactant or povidone . The result is a water-soluble material that releases free iodine when in solution...
- AntisepticAntisepticAntiseptics are antimicrobial substances that are applied to living tissue/skin to reduce the possibility of infection, sepsis, or putrefaction...