Lugol's iodine

Lugol's Iodine, also known as Lugol's Solution, first made in 1829, is a solution of elemental iodine and potassium iodide in water, named after the French physician J.G.A. Lugol. Lugol's iodine solution is often used as an antiseptic and disinfectant, for emergency disinfection of drinking water, and as a reagent for starch detection in routine laboratory and medical tests. These uses are possible since the solution is a source of effectively free elemental iodine, which is readily generated from the equilibrium between elemental iodine molecules and triiodide ion in the solution.

Lugol's Solution has been used traditionally to replenish iodine deficiency. Likewise, in the Chernobyl disaster some Lugol's solution was used as an emergency source of iodide to block radioactive iodine uptake, simply because it was widely available as a drinking water decontaminant, and pure potassium iodide without iodine (the preferred agent) was not available.

Since the 1970s Lugol's Solution has been available in tablet form, generally buffered. However, compounding chemists (pharmacists) had probably been creating tablets containing Lugol's Solution since the early 1900s. The tablet form is generally known as Iodoral.