Name: Potassium Chloride
CAS No: Potassium chloride [7447-40-7]
BP: Potassium Chloride JP: Potassium Chloride PhEur: Potassium Chloride USP: Potassium Chloride
Chloride of potash; chloropotassuril; dipotassium dichloride; E508; kalii chloridum; potassium monochloride.
Potassium chloride [7447-40-7]
KCl 74.55
See Section 4.
Potassium chloride is widely used in a variety of parenteral and nonparenteral pharmaceutical formulations. Its primary use, in parenteral and ophthalmic preparations, is to produce isotonic solutions. Potassium chloride is also used therapeutically in the treatment of hypokalemia. Many solid-dosage forms of potassium chloride exist including: tablets prepared by direct compression(1–4) and granulation;(5,6) effervescent tablets; coated, sustained-release tablets;(7–10) sustained-release wax matrix tablets;(11) microcapsules;(12) pellets; and osmotic pump formulations.(13,14) Experimentally, potassium chloride is frequently used as a model drug in the development of new solid-dosage forms, particularly for sustained-release or modified-release products. Potassium chloride is also used widely in the food industry as a dietary supplement, pH control agent, stabilizer, thickener, and gelling agent. It can also be used in infant formulations.
Potassium chloride occurs as odorless, colorless crystals or a white crystalline powder, with an unpleasant, saline taste. The crystal lattice is a face-centered cubic structure.
See Table I.
Acidity/alkalinity pH 7 for a saturated aqueous solution at 158C. Boiling point Sublimes at 15008C. Compressibility see Figure 1.(3,4) Density 1.99 g/cm3 ; 1.17 g/cm3 for a saturated aqueous solution at 158C. Melting point 7908C NIR spectra see Figure 2. Osmolarity A 1.19% w/v solution is iso-osmotic with serum. Particle size distribution Typical distribution(5) is 10% less than 30 mm, 50% less than 94 mm, and 90% less than 149 mm in size. Mean particle diameter is 108 mm. Finer powders may be obtained by milling. Solubility see Table II. Specific surface area 0.084 m2 /g (BET method)(5)
Potassium chloride tablets become increasingly hard on storage at low humidities. However, tablets stored at 76% relative humidity showed no increase or only a slight increase in hardness.(2) The addition of lubricants, such as 2% w/w magnesium stearate,(1) reduces tablet hardness and hardness on aging.(2) Aqueous potassium chloride solutions may be sterilized by autoclaving or by filtration. Potassium chloride is stable and should be stored in a well-closed container in a cool, dry place.
Potassium chloride reacts violently with bromine trifluoride and with a mixture of sulfuric acid and potassium permanganate. The presence of hydrochloric acid, sodium chloride, and magnesium chloride decreases the solubility of potassium chloride in water. Aqueous solutions of potassium chloride form precipitates with lead and silver salts. Intravenous aqueous potassium chloride solutions are incompatible with protein hydrolysate.
Potassium chloride occurs naturally as the mineral sylvite or sylvine; it also occurs in other minerals such as sylvinite, carnallite, and kainite. Commercially, potassium chloride is obtained by the solar evaporation of brine or by the mining of mineral deposits.
Potassium chloride is used in a large number of pharmaceutical formulations, including oral, parenteral, and topical preparations, both as an excipient and as a therapeutic agent.Potassium ions play an important role in cellular metabolism and imbalances can result in serious clinical effects. Orally ingested potassium chloride is rapidly absorbed from the gastrointestinal tract and excreted by the kidneys. Potassium chloride is more irritant than sodium chloride when adminstered orally, and ingestion of large quantities of potassium chloride can cause effects such as gastrointestinal irritation, nausea, vomiting, and diarrhea. High localized concentrations of potassium chloride in the gastrointestinal tract can cause ulceration: hence the development of the many enteric-coated and wax matrix sustained-release preparations that are available.(15) Although it is claimed that some formulations cause less ulceration than others, it is often preferred to administer potassium chloride as an aqueous solution. However, solutions have also been associated with problems, mainly due to their unpleasant taste. Parenterally, rapid injection of strong potassium chloride solutions can cause cardiac arrest; in the adult, solutions should be infused at a rate not greater than 750 mg/hour. Therapeutically, in adults, up to 10 g orally, in divided doses has been administered daily, while intravenously up to 6 g daily has been used. LD50 (guinea pig, oral): 2.5 g/kg(16) LD50 (mouse, IP): 1.18 g/kg LD50 (mouse, IV): 0.12 g/kg LD50 (mouse, oral): 0.38 g/kg LD50 (rat, IP): 0.66 g/kg LD50 (rat, IV): 0.14 g/kg LD50 (rat, oral): 2.6 g/kg
Observe normal precautions appropriate to the circumstances and quantity of material handled
GRAS listed. Accepted as a food additive in Europe. Included in the FDA Inactive Ingredients Database (injections, ophthalmic preparations, oral capsules, and tablets). Included in nonparenteral and parenteral medicines licensed in the UK. Included in the Canadian List of Acceptable Non-medicinal Ingredients.
Sodium chloride.
Each gram of potassium chloride represents approximately 13.4 mmol of potassium; 1.91 g of potassium chloride is approximately equivalent to 1 g of potassium. For diets where the intake of sodium chloride is restricted, salt substitutes for use in cooking or as table salt are available and contain mainly potassium chloride, e.g. LoSalt (Klinge Chemicals Ltd) is a blend of 2/3 potassium chloride and 1/3 sodium chloride with magnesium carbonate added as a flow-promoting agent. A specification for potassium chloride is contained in the Food Chemicals Codex (FCC).(17) The EINECS number for potassium chloride is 231-211-8. The PubChem Compound ID (CID) for potassium chloride is 4873.