Polyvinylpyrrolidone


Polyvinylpyrrolidone, also commonly called polyvidone or povidone, is a water-soluble polymer made from the monomer N-vinylpyrrolidone.

Uses

Medical

PVP was used as a plasma volume expander for trauma victims after the 1950s. It is not preferred as volume expander due to its ability to provoke histamine release and also interfere with blood grouping.
It is used as a binder in many pharmaceutical tablets; it simply passes through the body when taken orally.
PVP added to iodine forms a complex called povidone-iodine that possesses disinfectant properties. This complex is used in various products like solutions, ointment, pessaries, liquid soaps and surgical scrubs. It is known under the trade names Pyodine and Betadine, among a plethora of others.
It is used in pleurodesis. For this purpose, povidone iodine is equally effective and safe as talc, and may be preferred because of easy availability and low cost.
PVP is used in some contact lenses and their packaging solutions. It reduces friction, thus acting as a lubricant, or wetting agent, built into the lens. Examples of this use include Bausch & Lomb's Ultra contact lenses with MoistureSeal Technology and Air Optix contact lens packaging solution.
PVP is used as a lubricant in some eye drops, e.g. Bausch & Lomb's Soothe.

Technical

PVP is also used in many technical applications:
PVP binds to polar molecules exceptionally well, owing to its polarity. This has led to its application in coatings for photo-quality ink-jet papers and transparencies, as well as in inks for inkjet printers.
PVP is also used in personal care products, such as shampoos and toothpastes, in paints, and adhesives that must be moistened, such as old-style postage stamps and envelopes. It has also been used in contact lens solutions and in steel-quenching solutions. PVP is the basis of the early formulas for hair sprays and hair gels, and still continues to be a component of some.
As a food additive, PVP is a stabilizer and has E number E1201. PVPP is E1202. It is also used in the wine industry as a fining agent for white wine and some beers.
In molecular biology, PVP can be used as a blocking agent during Southern blot analysis as a component of Denhardt's buffer. It is also exceptionally good at absorbing polyphenols during DNA purification. Polyphenols are common in many plant tissues and can deactivate proteins if not removed and therefore inhibit many downstream reactions like PCR.
In microscopy, PVP is useful for making an aqueous mounting medium.
PVP can be used to screen for phenolic properties, as referenced in a 2000 study on the effect of plant extracts on insulin production.

Safety

The U.S. Food and Drug Administration has approved this chemical for many uses, and it is generally considered safe. However, there have been documented cases of allergic reactions to PVP/povidone, particularly regarding subcutaneous use and situations where the PVP has come in contact with autologous serum and mucous membranes. For example, a boy having an anaphylactic response after application of PVP-Iodine for treatment of impetigo was found to be allergic to the PVP component of the solution. A woman, who had previously experienced urticaria from various hair products, later found to contain PVP, had an anaphylactic response after povidone-iodine solution was applied internally. She was found to be allergic to PVP. In another case, a man experiencing anaphylaxis after taking acetaminophen tablets orally was found to be allergic to PVP.
Povidone is commonly used in conjunction with other chemicals. Some of these, such as iodine, are blamed for allergic responses, although testing results in some patients show no signs of allergy to the suspect chemical. Allergies attributed to these other chemicals may possibly be caused by the PVP instead.

Properties

PVP is soluble in water and other polar solvents. For example, it is soluble in various alcohols, such as methanol and ethanol, as well as in more exotic solvents like the deep eutectic solvent formed by choline chloride and urea. When dry it is a light flaky hygroscopic powder, readily absorbing up to 40% of its weight in atmospheric water. In solution, it has excellent wetting properties and readily forms films. This makes it good as a coating or an additive to coatings.
A 2014 study found fluorescent properties of PVP and its oxidized hydrolyzate.

History

PVP was first synthesized by Walter Reppe and a patent was filed in 1939 for one of the derivatives of acetylene chemistry. PVP was initially used as a blood plasma substitute and later in a wide variety of applications in medicine, pharmacy, cosmetics and industrial production.

Cross-linked derivatives