Lugol's is 2.5 mg of iodine and 3.75 mg of potassium iodide and water(tincture has alcohol) per drop of 5% solution.
Iodoral is the equivelent but in pill form and may have fillers or binders.
SSKI is super saturated potassium iodide and water.
Potassium iodide is the salt of iodine.
The reason for combining both is because the some body parts prefer iodine and others prefer iodide.
Some of the potassium iodide will convert in the body to iodine.
Thyroid needs 3% prefers iodide (50mg iodide)(hence the high doses for radiation exposure)
Skin needs 20% and prefers iodide
Salivary Glands prefer iodide
Muscles (650mg) and fat needs(700mg iodine) 70%
Breast tissue needs 3-5 mg / day minumum and prefers iodine
Prostate prefers iodine
Stomach prefers iodine
Lungs prefer iodide
Entire body needs 1500 mg 2gm total