Calcium Chloride

Basic Information

Name: Calcium Chloride

CAS No: Calcium chloride anhydrous [10043-52-4] Calcium chloride dihydrate [10035-04-8] Calcium chloride hexahydrate [7774-34-7]

Functional Categories

Antimicrobial preservative Therapeutic agent Water-absorbing agent

1. Nonproprietary Names

BP: Calcium Chloride Dihydrate Calcium Chloride Hexahydrate JP: Calcium Chloride Hydrate PhEur: Calcium Chloride Dihydrate Calcium Chloride Hexahydrate USP-NF: Calcium Chloride Note that the JP XV and USP32–NF27 monographs list the dihydrate form.

2. Synonyms

Calcii chloridum dihydricum; calcii chloridum hexahydricum.

3. Chemical Name & CAS Registry

Calcium chloride anhydrous [10043-52-4] Calcium chloride dihydrate [10035-04-8] Calcium chloride hexahydrate [7774-34-7]

4. Empirical Formula & Molecular Weight

CaCl2 110.98 (for anhydrous) CaCl22H2O 147.0 (for dihydrate) CaCl26H2O 219.1 (for hexahydrate)

5. Structural Formula

See Section 4.

6. Applications

The main applications of calcium chloride as an excipient relate to its dehydrating properties and, therefore, it has been used as an antimicrobial preservative, as a desiccant, and as an astringent in eye lotions. Therapeutically, calcium chloride injection 10% (as the dihydrate form) is used to treat hypocalcemia.(1)

7. Description

Calcium chloride occurs as a white or colorless crystalline powder, granules, or crystalline mass, and is hygroscopic (deliquescent).

8. Pharmacopeial Specifications

See Table I.

9. Typical Properties

Acidity/alkalinity pH = 4.5–9.2 (5% w/v aqueous solution) Boiling point >16008C (anhydrous) Density (bulk) 0.835 g/cm3 (dihydrate) Melting point 7728C (anhydrous); 1768C (dihydrate); 308C (hexahydrate). Solidification temperature 28.5–308C (hexahydrate) Solubility Freely soluble in water and ethanol (95%); insoluble in diethyl ether.

10. Stability & Storage

Calcium chloride is chemically stable; however, it should be protected from moisture. Store in airtight containers in a cool, dry place.

11. Incompatibilities

Calcium chloride is incompatible with soluble carbonates, phosphates, sulfates, and tartrates.(2) It reacts violently with bromine trifluoride, and a reaction with zinc releases explosive hydrogen gas. It has an exothermic reaction with water, and when heated to decomposition it emits toxic fumes of chlorine.

12. Method of Manufacture

Calcium chloride is a principal byproduct from the Solvay process.

13. Safety

Calcium chloride is used in topical, ophthalmic, and injection preparations. The pure form of calcium chloride is toxic by intravenous, intramuscular, intraperitoneal, and subcutaneous routes, and moderately toxic by ingestion, causing stomach and heart disturbances. It is a severe eye irritant and can cause dermatitis. LD50 (mouse, IP): 0.21 g/kg(3) LD50 (mouse, IV): 0.042 g/kg LD50 (mouse, oral): 1.94 g/kg LD50 (mouse, SC): 0.82 g/kg LD50 (rat, IM): 0.025 g/kg LD50 (rat, IP): 0.26 g/kg LD50 (rat, oral): 1.0 g/kg LD50 (rat, SC): 2.63 g/kg

14. Handling Precautions

Observe normal precautions appropriate to the circumstances and quantity of the material handled. Calcium chloride is irritating to eyes, the respiratory system, and skin. Gloves, eye protection, respirator, and other protective clothing should be worn.

15. Regulatory Status

GRAS listed. Included in the FDA Inactive Ingredients Database (injections, ophthalmic preparations, suspensions, creams). Included in medicines licensed in the UK (eye drops; intraocular irrigation; vaccines; injection powders for reconstitution; nebulizer solution; oral suspension).

17. Comments

The dissolution of calcium chloride in water is an exothermic reaction and, along with other excipients such as sodium sulfate, sodium acetate, and water, it has a potential application in hot packs.(4) Calcium chloride has been used to control the release of active ingredients from solid oral dosage forms by crosslinking pectin,(5) or by its interaction with chitosan.(6) A specification for calcium chloride is contained in the Food Chemicals Codex (FCC).(7) The EINECS number for calcium chloride is 233-140-8. The PubChem Compound ID (CID) for calcium chloride is 5284359