As a synthetic water-soluble polymer compound, PVP possesses the general properties of such compounds, including colloidal protection, film-forming ability, adhesiveness, hygroscopicity, and solubilizing or coagulating effects. However, its most distinctive and highly valued characteristics are its excellent solubility and physiological compatibility. Among synthetic polymers, it is rare to find one like PVP that is soluble in both water and most organic solvents, exhibits very low toxicity, and has good physiological compatibility.