Here are some differences between povidone-iodine and Lugol's iodine:
Chemical composition
Povidone-iodine is a chemical complex of iodine and the polymer povidone (polyvinylpyrrolidone, PVP). Lugol's iodine is a solution of iodine.
Stability
Povidone-iodine solutions are more stable than Lugol's iodine solutions. For example, a 2% povidone-iodine solution can remain unchanged for a year at room temperature.
Uses
Lugol's iodine is used for cauterizing the cornea after corneal scraping. Povidone-iodine can be used topically to treat equine keratomycosis. It can also kill bacteria, viruses, fungi, spores, and protozoa.