General description

Potassium Iodide is a metal halide composed of potassium and iodide with thyroid protecting and expectorant properties.Potassium iodide is an odorless white solid. Sinks and mixes with water. (USCG, 1999). Potassium iodide is a metal iodide salt with a K(+) counterion. It is a scavenger of hydroxyl radicals. It has a role as a radical scavenger and an expectorant. It contains an iodide.

Chemical and Physical property

Potassium iodide can react chemically with many substances through I - in ki. Among halogen ions, I - has the largest radius, so I - is easy to form complexes with transition metal ions and D-region metal ions; The reducibility of I - is stronger than that of Br - and Cl -, and it is easy to be oxidized to I2; The solubility of iodide is similar to that of chloride and bromide. The iodides of Ag +, Hg2 +, Cu +, Hg2 + and Pb2 + are insoluble, and most of the precipitates have color. Colorless or white crystalline powder, density 3.13g/cm3, melting point 618 ℃, boiling point 1345 ℃, easily soluble in water and ethanol. The aqueous solution darkens with light and ionizes iodine. 

Application and Pharmacology

Potassium iodide can block absorption of radioactive iodine by the thyroid gland through flooding the thyroid with non-radioactive iodine and preventing intake of radioactive molecules, thereby protecting the thyroid from cancer causing radiation. In addition, this agent acts as an expectorant by increasing secretion of respiratory fluids resulting in decreased mucus viscosity. 

Potassium iodide is an anti-fungal drug listed in the World Health Organization (WHO) essential drug list and generally thought to be the first choice for cutaneous sporotrichosis including fixed and lymphocutaneous types, in developing countries. No randomized controlled trials (RCTs) of oral potassium iodide versus placebo were found and thus its efficacy and safety could not be analysed in this review. There is a need for randomised placebo controlled trials of oral potassium iodide in this area. Sporotrichosis is a subacute or chronic disease, usually afecting the skin caused by a dimorphic (existing in two forms), aerobic (oxygen requiring) fungus called Sporothrix schenckii. Oral potassium iodide is widely used for cutaneous sporotrichosis in clinical medicine with more and more reports published. However, the benefits and adverse reactions of these treatment Oral potassium iodide is widely used for cutaneous sporotrichosis in clinical medicine with more and more reports published[1].

Synthesis

Potassium iodide belongs to iodine preparation, and its preparation is potassium iodide tablets. The synthesis process of potassium iodide is as follows: iodine is dissolved in potassium hydroxide solution to form a mixture of potassium iodide and potassium iodate, evaporated to dryness, mixed with carbon powder and heated to reduce potassium iodate to obtain potassium iodide. The relevant reaction formula is following：

Figure 1 the synthesis formula of Potassium Iodide

Storage and Safety

A saturated solution of potassium iodide is administered in a slowly ascending dose beginning with 3 drops 3 times per day increasing until limited by adverse efects, or until a clinical response is achieved or until a maximum dose of roughly 40 drops per day is reached, (equivalent to 400 mg of iodine). The medication is relatively cheap but is unpalatable[2].

Packaging potassium iodide shall be packed in cartons lined with polyethylene plastic bags. Potassium iodide for storage and transportation protection shall be stored in a cool, dry and ventilated warehouse, and shall not be stacked in the open air or shed. Avoid direct sunlight and moisture to prevent deterioration of goods. It shall be isolated from inflammable, toxic, acid and volatile odor. It shall not be stored and transported together. The warehouse shall be kept clean. Handle with care during handling to prevent throwing and falling, so as to avoid package damage. Prevent rain and exposure to the sun. The means of transportation shall be covered and cleaned to avoid commodity pollution, so as to ensure the quality. The storage period should not exceed one year. If there is a fire, it can be put out with water

Reference

1.Oral potassium iodide for the treatment of sporotrichosis

2.Yang GAOSONG, Zhao Liankui, Li Dongjun, Zhao Hongliang, Zheng Wenli, Li Ming, sun ruipeng, Zhang Xiangtao, Li Shiyuan, Wang Yibing Effect of potassium iodide on collagen synthesis of human skin fibroblasts [J] Shandong medicine, 2013,53 (39): 25-28