Polyvinylpolypyrrolidone
Polyvinylpolypyrrolidone is a highly cross-linked modification of polyvinylpyrrolidone.
This cross-linked form of PVP is used as a disintegrant in pharmaceutical tablets.
PVPP is insoluble in water, though it still absorbs water and swells very rapidly generating a swelling force. This property makes it useful as a disintegrant in tablets.
PVPP can be used as a drug, taken as a tablet or suspension to absorb compounds that cause diarrhea.
It is also used as a fining to extract impurities. It is used in winemaking. Using the same principle it is used to remove polyphenols in beer production and thus clear beers with stable foam are produced. One such commercial product is called Polyclar. PVPP forms bonds similar to peptidic bonds in protein and that is why it can precipitate tannins the same way as proteins do.
PVPP is used as a stabiliser.