ABSTRACT
Polyvinylpyrrolidone (PVP) has been widely used medically in the manufacture of tablets and for both diagnostic and therapeutic purposes since the early 1940s. The major use of PVP in quantitative terms has been in the manufacture of tablets. PVP was consumed in trace amounts in beer, wine and vinegar as a residual contaminant when it was used as a clarifying agent, but PVP is no longer used for this purpose, having been replaced by Polyvinylpolypyrrolidone. In the United States PVP is used as a stabilizer and dispersant for food dyes and in concentrated liquid sweeteners; and it has been used in coatings on candy, fresh fruit and paper for food wrapping. Substances may pass across membranes by a number of mechanisms, including simple diffusion, facilitated diffusion, active transport and special mechanisms such as pinocytosis. Most xenobiotics cross membranes by simple diffusion, and for low molecular weight PVPs this is the major mechanism involved.
