Fast dissolving polymers such as polyvinyl-pyrrolidone (PVP) are efficient delivery vehicles of poorly water-soluble and poorly permeable drugs. PVP is hydrophilic and compatible with a wide array of polymers and copolymers; therefore it is used extensively in the pharmaceutical industry to increase the dissolution of commonly used drugs.
Problems in achieving expected rate of drug dissolution may be attributed to a high content of drug in the solid solution due to:
- Molecular dispersion of the drug in the carrier
- Precipitation of a metastable polymorph of the drug with a solubility higher than that of a stable form