Ammonium Chloride

Basic Information

Name: Ammonium Chloride

CAS No: Ammonium chloride [12125-02-9]

Functional Categories

Acidifying agent Therapeutic agent

1. Nonproprietary Names

BP: Ammonium Chloride PhEur: Ammonium Chloride USP: Ammonium chloride

2. Synonyms

Ammonii chloridum; ammonium muriate; E510; sal ammoniac; salmiac.

3. Chemical Name & CAS Registry

Ammonium chloride [12125-02-9]

4. Empirical Formula & Molecular Weight

NH4Cl 53.49

5. Structural Formula

See Section 4.

6. Applications

Ammonium chloride is used as an acidifying agent in oral formulations. It is also used as a food additive and antiseptic agent.(1) Ammonium chloride is used in the treatment of severe metabolic alkalosis to maintain the urine at an acid pH in the treatment of some urinary tract disorders or in forced acid diuresis.(2–4) It is also used as an expectorant in cough medicines.(5

7. Description

Ammonium chloride occurs as colorless, odorless crystals or crystal masses. It is a white, granular powder with a cooling, saline taste. It is hygroscopic and has a tendency to cake.

8. Pharmacopeial Specifications

See Table I.

9. Typical Properties

Acidity/alkalinity pH = 4.5–5.5 (5.5% w/w aqueous solutions at 258C) Density (bulk) 0.6–0.9 g/cm3 Hygroscopicity Hygroscopic with potential to cake. Melting point Decomposes at 3388C; sublimes without melting.(6) Solubility Soluble in water; hydrochloric acid and sodium chloride decrease its solubility in water. Also soluble in glycerin; sparingly soluble in methanol and ethanol. Almost insoluble in acetone, ether, and ethyl acetate. Specific gravity 1.527 g/cm3 Vapor pressure 133.3 Pa (1 mmHg) at 1608C

10. Stability & Storage

Ammonium chloride is chemically stable. It decomposes completely at 3388C to form ammonia and hydrochloric acid. Store in airtight containers in a cool, dry place.

11. Incompatibilities

Ammonium chloride is incompatible with strong acids and strong bases. It reacts violently with ammonium nitrate and potassium chlorate, causing fire and explosion hazards. It also attacks copper and its compounds.

12. Method of Manufacture

Ammonium chloride is prepared commercially by reacting ammonia with hydrochloric acid.

13. Safety

Ammonium chloride is used in oral pharmaceutical formulations. The pure form of ammonium chloride is toxic by SC, IV, and IM routes, and moderately toxic by other routes. Potential symptoms of overexposure to fumes are irritation of eyes, skin, respiratory system: cough, dyspnea, and pulmonary sensitization.(7)Ammonium salts are an irritant to the gastric mucosa and may induce nausea and vomiting. LD50 (mouse, IP): 1.44 g/kg(8) LD50 (mouse, oral): 1.3 g/kg LD50 (rat, IM): 0.03 g/kg(9) LD50 (rat, oral): 1.65 g/kg(10)

14. Handling Precautions

Observe normal precautions appropriate to the circumstances and quantity of the material handled. All grades of ammonium chloride must be kept well away from nitrites and nitrates during transport and storage. They must be stored in a dry place, and effluent must not be discharged into the drains without prior treatment. Ammonium chloride decomposes on heating, producing toxic and irritating fumes (nitrogen oxides, ammonia, and hydrogen chloride).

15. Regulatory Status

GRAS listed. Included in the FDA Inactive Ingredients Database (oral syrup, tablets). Accepted for use as a food additive in Europe. Included in medicines licensed in the UK (eye drops; oral syrup).

16. Related Substances

Ammonia solution.

17. Comments

Ammonium chloride has the ability to cross the red blood cell membrane, and a solution that is isotonic to blood will still cause hemolytic rupture because it acts as a hypotonic solution. A specification for ammonium chloride is contained in the Food Chemicals Codex (FCC).(11) The EINECS number for ammonium chloride is 235-186-4. The PubChem Compound ID (CID) for ammonium chloride is 25517