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Polyvinylpyrrolidone (PVP) is a water-soluble polymer made from the monomer N-vinylpyrrolidone: Polyvinylpolypyrrolidone (PVPP, crospovidone) is a highly cross-linked modification of PVP.
[edit] PropertiesPVP is soluble in water and other polar solvents. In water it has the useful property of Newtonian viscosity. When dry it is a light flaky powder, which readily absorbs 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. [edit] HistoryPVP was first synthesized by Prof. Walter Reppe and a patent was filed in 1939 for one of the most interesting 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. [edit] UsesThe monomer is extremely toxic to aquatic life. However, the polymer PVP was used as a blood plasma expander for trauma victims after the first half of the 20th century.[clarification needed] It is used as a binder in many pharmaceutical tablets; it simply passes through the body when taken orally. However, autopsies have found that crospovidone does contribute to pulmonary vascular injury in substance abusers who have injected pharmaceutical tablets intended for oral consumption.[1] The long-term effects of crospovidone within the lung are unknown. PVP added to Iodine forms a complex called (Povidone-iodine[2]) that possesses disinfectant properties. This complex is used in various products like solutions, ointment, pessaries, liquid soaps and surgical scrubs. It is known for instance under the trade name Betadine. 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. Other references state that as polyvinyl pyrrolidone and its derivatives are fully from mineral synthetic[3] origin. Therefore, its use in the production should not be a problem for vegans. 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 adsorbing 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. PVP is also used in many technical applications:
[edit] Cross-linked derivativesA cross-linked form of PVP is also used as a disintegrant (see also excipients) in pharmaceutical tablets.[5][6] It is also known as cross-linked polyvinyl pyrrolidone, Polyvinyl Polypyrrolidone (PVPP), crospovidone, crospolividone. Basically, PVPP is a highly cross-linked version of PVP, which makes it insoluble in water but it still absorbs water and swells very rapidly and generate a swelling force. That is why it can be used as a disintegrant in tablets. It is also used to bind impurities to remove them from solutions. It is also used as a fining to extract impurities (via agglomeration followed by filtration). Using the same principle it is used to remove polyphenols in beer production and thus clear beers with stable foam are produced.[7] PVPP can be used as a drug, taken as a tablet or suspension to absorb compounds (so-called Endotoxins) causing diarrhoea. (Cf. bone char, charcoal.) [edit] See also[edit] Notes
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