Food additives Europe numbers: E510
Functional Category
Alkalizing agent
Applications in Pharmaceutical Formulation
Ammonia solution is typically not used undiluted in pharmaceutical applications. Generally, it is used as a buffering agent or to adjust the pH of solutions. Most commonly, ammonia solution (the concentrated form) is used to produce more dilute ammonia solutions.Therapeutically, dilute ammonia solution is used as a reflex stimulant in ‘smelling salts’, as a rubefacient, and as a counterirritant to neutralize insect bites or stings.
Description
Strong ammonia solution occurs as a clear, colorless liquid having an exceedingly pungent, characteristic odor. The PhEur 6.0 states that concentrated ammonia solution contains not less than 25.0% and not more than 30.0% w/w of ammonia (NH3). The USP32– NF27 states that strong ammonia solution contains not less than 27.0% and not more than 31.0% w/w of ammonia .
Stability and Storage Conditions
On exposure to the air, ammonia solution rapidly loses ammonia. Ammonia solution should be stored in a well-closed container, protected from the air, in a cool, dry place. The storage temperature should not exceed 208C
Incompatibilities
Ammonia solution reacts vigorously with sulfuric acid or other strong mineral acids and the reaction generates considerable heat; the mixture boils.
Safety
Ingestion of strong solutions of ammonia is very harmful and causes severe pain in the mouth, throat, and gastrointestinal tract as well as severe local edema with cough, vomiting, and shock. Burns to the esophagus and stomach may result in perforation. Inhalation of the vapor causes sneezing, coughing, and, in high concentration, pulmonary edema. Asphyxia has been reported. The vapor is irritant to the eyes. Strong solutions are harmful when applied to the conjunctiva and mucous membranes. Topical application of even dilute ammonia solutions, used to treat insect bites, has caused burns, particularly when used with a subsequent dressing.(2–4) When used as an excipient, ammonia solution is generally present in a formulation in a highly diluted form.