Polyvinylpyrrolidone Research Paper

Polyvinylpyrrolidone (PVP) is a synthetic polymer made from a monomer N_ vinylpyrrolidone. Its known as Povidone in the USP. PVP has many applications in pharmacy, medicine, industrial production and cosmetics (79).
PVP appear as a free flowing white powder with a characteristic odor. It is available commercially with different K values. The K-value is an indication of the mean molecular weight which ranges from 2 to 3KDa for PVP-K12 and from 1000 to 1500KDa for PVP-K90 .It is Soluble in water and in polar solvents. Its insoluble in ethers, ketones, esters and hydrocarbons. Its glass transition temperature varries between 130-176ºC depending on the molecular weight (80).
The water-soluble grades of polyvinylpyrrolidone are obtained by free-radical polymerization of vinylpyrrolidone in
It was proved in many studies that using PVP as a carrier for poorly water soluble drugs improves their solubility, and hence enhance the bioavailability. Shah J. et al. (2009) reported linear increase in valdecoxib solubility increases and enhancement of dissolution rate as PVP-K30 concentration. This enhancement may be related to wettability improvement and reduction in the crystallinity (82).
These findings agree with what was reported in other studies such carbamazepine (83), Paracetamol (84), ketoprofen (85) and Aceclofenac (86).
PVP can give rise to a high energy solid state or inhibit the crystallisation of the drug by the viscosity induced by PVP that keep amorphous solid state. The formation of high-energy complexes, the presence of drug in amorphous state and the interaction between PVP and drugs such as hydrogen bonding can explain the solubility enhancement