The cross-linked form of PVP is used as a disintegrant (see also excipients) in pharmaceutical tablets.. 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 generates a swelling force. That is why it can be used as a disintegrant in tablets.
It is also used as a fining to extract impurities (via agglomeration followed by filtration). 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 formed bonds similar to peptidic bonds in protein (especially, like proline residues) and that is why it can precipitate tannins the same way as proteins do.
PVPP has E number code E1202 and is used as a stabiliser.
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