Calcium Chloride
(kal' see um klor' ide).

CaCl2·2H2O 147.01
Calcium chloride dihydrate     [10035-04-8].
CaCl2 110.98
Anhydrous     [10043-52-4].
DEFINITION
Calcium Chloride contains an amount of CaCl2 equivalent to NLT 99.0% and NMT 107.0% of CaCl2·2H2O.
IDENTIFICATION
•  A. Identification Tests—General, Calcium 191
Sample solution:  100 mg/mL
Acceptance criteria:  Meets the requirements
•  B. Identification Tests—General, Chloride 191
Sample solution:  100 mg/mL
Acceptance criteria:  Meets the requirements
ASSAY
•  Procedure
Sample solution:  Dissolve 1 g of Calcium Chloride in a mixture of water and 3 N hydrochloric acid (100:5). Transfer the solution to a 250-mL volumetric flask, and dilute with water to volume.
Analysis:  Pipet 50 mL of the Sample solution into a suitable container, and add 100 mL of water, 15 mL of 1 N sodium hydroxide, and 300 mg of hydroxy naphthol blue. Titrate with 0.05 M edetate disodium VS until the solution is deep blue. Each mL of 0.05 M edetate disodium is equivalent to 7.351 mg of calcium chloride dihydrate (CaCl2·2H2O).
Acceptance criteria:  99.0%–107.0% of CaCl2·2H2O
IMPURITIES
•  Aluminum 206
[Note—Perform if labeled as intended for use in hemodialysis. ]
Test preparation:  Use a 2.0-g sample.
Acceptance criteria:  NMT 1 ppm
•  Heavy Metals 231
Sample solution:  80 mg/mL
Acceptance criteria:  NMT 10 ppm
•  Iron, Aluminum, and Phosphate
Sample solution:  50 mg/mL
Analysis:  Add 2 drops of 3 N hydrochloric acid and 1 drop of phenolphthalein TS to the Sample solution. Then add ammonium chloride–ammonium hydroxide TS, dropwise, until the solution is faintly pink. Add 2 drops in excess, and heat the liquid to boiling.
Acceptance criteria:  No turbidity or precipitate is produced.
•  Limit of Magnesium and Alkali Salts
Sample solution:  20 mg/mL
Analysis:  To 50 mL of Sample solution add 500 mg of ammonium chloride. Heat the solution, and boil for 1 min. Rapidly add 40 mL of oxalic acid TS, and stir vigorously until precipitation is well established. Add immediately to the warm mixture 2 drops of methyl red TS and then 6 N ammonium hydroxide, dropwise, until the mixture is just alkaline. Cool to room temperature. Transfer to a 100-mL graduated cylinder, dilute with water to 100 mL, mix, and allow to stand for 4 h or overnight. Filter, and to 50 mL of the clear filtrate in a platinum dish, add 0.5 mL of sulfuric acid, and evaporate the mixture on a steam bath to a small volume. Carefully heat over a free flame to dryness, and continue heating to complete decomposition and volatilization of ammonium salts. Finally, ignite the residue to constant weight.
Acceptance criteria:  The weight of the residue is NMT 5 mg (1.0%).
SPECIFIC TESTS
•  pH 791
Sample solution:  50 mg/mL
Acceptance criteria:  4.5–9.2
ADDITIONAL REQUIREMENTS
•  Packaging and Storage: Preserve in tight containers.
•  Labeling: Where Calcium Chloride is intended for use in hemodialysis, it is so labeled.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Domenick Vicchio, Ph.D.
Senior Scientific Liaison
1-301-998-6828
(SM42010) Monographs - Small Molecules 4
USP35–NF30 Page 2450
Pharmacopeial Forum: Volume No. 29(5) Page 1436