Name: China Source Factory Supply High Purity Best Price Polyvinylpyrrolidone (PVPP) CAS 25249-54-1
Brand: Wuhan Fortuna Chemical Co., Ltd.

Specifications of Polyvinylpyrrolidone (PVPP) CAS 25249-54-1 Wholesale & Bulk

Items	Specifications	Results
Appearance	Hygroscopic, white or yellowish-white powder or flakes.	White powder
Solubility	Insoluble in water,in ordinary organic solvents.	Complies
Identification	A,B,C,D	Complies Type B
PH(in 1% suspension)	5.0-8.0	6.7
Loss on drying	≤5.0%	1.8%
Nitrogen content	11.0-12.8	12.2
Peroxides	≤1000ppm	240ppm
Vinylpyrrolidinone	≤10ppm	2.4ppm
Residue on ignition	≤0.1%	0.06%
Heavy metals	≤10ppm	Complies
Water-soluble substances	≤1.5%	0.36%
Particle size	30-60μm	Complies
Residual Solvent	Meet with requirement	Complies
Total aerobic counts	≤100cfu/g	＜100cfu/g
Total combined yeast and mold	≤10cfu/g	＜10cfu/g
E.Coli	Absence/lg	Complies
Salmonella spp	Absence/lg	Complies
Pseudomona aerugonosa	Absence/lg	Complies
Staphylococus aureus	Absence/lg	Complies
Conclusion	The product complies with enterprise standard.

Parameters of Polyvinylpyrrolidone (PVPP) CAS 25249-54-1

Product parameters
Cas number:	25249-54-1
Appearance:	White or yellowish-white powder
Purity:	Nitrogen 11.0 – 12.8%
Package details:	20kg/drum
Brand:	Fortunachem

Crospovidone is an insoluble, cross-linked version of the polymer Povidone. Think of it as a highly absorbent, sponge-like network of long chemical chains. Its key property is that it swells dramatically in water without dissolving, which makes it an extremely effective tablet disintegrant in pharmaceuticals.

Detailed Chemical Breakdown

1. Chemical Identity and Structure

Chemical Name: Cross-linked Polyvinylpyrrolidone (PVPP)
CAS Number: 9003-39-8
Monomer: The base unit is N-Vinylpyrrolidone.
Polymerization: It is produced by the bridging polymerization of N-Vinylpyrrolidone. This "bridging" or cross-linking is the key to its properties.

2. The Concept of Cross-Linking

This is the most important chemical concept to understand:

Regular Povidone (PVP): Made by polymerizing N-Vinylpyrrolidone into long, linear chains. These chains are water-soluble.
Crospovidone (PVPP): During its manufacturing, "cross-linking agents" (often compounds with two double bonds) create bridges that chemically tie these long chains together into a vast, three-dimensional network.

This cross-linked structure is why it's insoluble. While water can penetrate the network and cause it to swell, the chemical bonds holding the network together are too strong to allow the individual polymer chains to break away and dissolve.

The simplified chemical structure of its repeating unit is:

║

[N-(C₃H₆)-C] (Within a polyvinyl backbone)

(CH₂-CH)_n

3. Key Chemical and Functional Properties

Property	Chemical Reason	Functional Consequence
Insolubility	The extensive, covalently bonded 3D network.	Does not form a gel or sticky solution; remains as discrete particles.
High Swelling Capacity	The polymer chains are hydrophilic (water-loving) and repel each other when hydrated, but are held in place by cross-links.	Absorbs water and expands rapidly, exerting immense swelling pressure.
Capillary Action	The dry powder has a fine, porous particle structure.	Draws water into a tablet very quickly via capillaries, enhancing the swelling effect.
Chemically Inert	The polyvinylpyrrolidone structure is stable and non-reactive.	Does not interact with the active pharmaceutical ingredients (APIs), ensuring drug stability.

4. Primary Function: Tablet Disintegration

This is almost exclusively why Crospovidone is used. The mechanism is physical and mechanical:

Water Uptake: When a tablet containing Crospovidone is exposed to water (in the stomach or a dissolution vessel), the Crospovidone particles act like microscopic sponges, drawing water into the tablet through capillary action.
Swelling: The Crospovidone particles absorb the water and swell dramatically in volume.
Pressure Generation: This swelling creates enormous, radially outward stress within the tightly compressed tablet matrix.
Breakup: This internal stress overcomes the bonding forces holding the tablet together, causing it to break apart rapidly into smaller granules and primary powder particles. This process is known as disintegration.

This is crucial because disintegration is the first step before the drug can dissolve and be absorbed by the body.

Summary

Aspect	Description
What it is	An insoluble, cross-linked polymer of N-vinylpyrrolidone.
Chemical Key	The 3D network created by cross-linking, which prevents dissolution but allows swelling.
Primary Role	A super-disintegrant in pharmaceutical tablets and capsules.
Mechanism	Acts by capillary action and swelling, breaking tablets apart through physical pressure.
Advantage	Highly effective at low concentrations (typically 2-5% of tablet weight), inert, and does not gel.

In essence, from a chemical perspective, Crospovidone is an ingeniously designed polymer whose insolubility is its greatest asset. Its cross-linked structure allows it to perform a critical physical function—rapidly breaking apart tablets—without chemically interfering with the medicine itself.