Carboxymethylcellulose Calcium
Cellulose, carboxymethyl ether, calcium salt;
Cellulose carboxymethyl ether calcium salt
[9050-04-8].
(kar box'' ee meth'' il sel' ue lose kal' see um).
Cellulose, carboxymethyl ether, calcium salt;
Cellulose carboxymethyl ether calcium salt
[9050-04-8].DEFINITION
Carboxymethylcellulose Calcium is the calcium salt of a polycarboxymethyl ether of cellulose.
IDENTIFICATION
• A. Procedure
Sample solution:
Shake thoroughly 0.1 g of Carboxymethylcellulose Calcium with 10 mL of water, followed by 2 mL of 1 N sodium hydroxide, and allow to stand for 10 min.
[Note—Save the unused portion of the Sample solution for use in Identification tests B and C. ]
Analysis:
To 1 mL of the Sample solution add water to make 5 mL. To 1 drop of the resulting solution, add 0.5 mL of chromotropic acid TS, and heat in a water bath for 10 min.
Acceptance criteria:
A red-purple color develops.
• B. Procedure
Analysis:
Shake 5 mL of the Sample solution prepared in Identification test A with 10 mL of acetone.
Acceptance criteria:
A white, flocculent precipitate is formed.
• C. Procedure
Analysis:
Shake 5 mL of the Sample solution prepared in Identification test A with 1 mL of ferric chloride TS.
Acceptance criteria:
A brown, flocculent precipitate is formed.
• D. Identification Tests—General, Calcium 
191
:
191:
Analysis:
Ignite 1 g to ash, dissolve the residue in 10 mL of water and 5 mL of 6 N acetic acid, and filter, if necessary. Boil the filtrate, cool, and neutralize with 6 N ammonium hydroxide.
Acceptance criteria:
Meets the requirements
IMPURITIES
Inorganic Impurities
• Residue on Ignition 281:
10.0%–20.0%; use 1.0 g, previously dried
281:
10.0%–20.0%; use 1.0 g, previously dried
• Heavy Metals, Method II 231:
NMT 20 ppm, adding 1 mL of hydroxylamine hydrochloride solution (1 in 5) to the solution of the residue
231:
NMT 20 ppm, adding 1 mL of hydroxylamine hydrochloride solution (1 in 5) to the solution of the residue
• Chloride and Sulfate, Chloride 221
221
Sample stock solution:
Shake thoroughly 0.80 g with 50 mL of water, dissolve in 10 mL of 1 N sodium hydroxide, and add water to make 100 mL.
[Note—Retain a portion of the Sample stock solution for use in the test for Sulfate. ]
Sample solution:
Heat 20 mL of the Sample stock solution with 10 mL of 2 N nitric acid in a water bath until a flocculent precipitate is formed, cool, centrifuge, and remove the supernatant. Wash the precipitate with three 10-mL portions of water by centrifuging each time, combine the supernatant and the washings, add water to make 100 mL, and mix.
Acceptance criteria:
A 25-mL portion of the Sample solution shows no more chloride than is contained in 0.20 mL of 0.020 N hydrochloric acid (0.36%).
• Chloride and Sulfate, Sulfate 221
221
Sample solution:
Heat 10 mL of the Sample stock solution prepared in the test for Chloride with 1 mL of hydrochloric acid in a water bath until a flocculent precipitate is formed. Cool, centrifuge, and remove the supernatant. Wash the precipitate with three 10-mL portions of water by centrifuging each time, combine the supernatant and the washings, add water to make 100 mL, and mix.
Acceptance criteria:
A 25-mL portion of the Sample solution shows no more sulfate than is contained in 0.21 mL of 0.020 N sulfuric acid (1.0%).
SPECIFIC TESTS
• Alkalinity:
Shake thoroughly 1.0 g with 50 mL of freshly boiled and cooled water, and add 2 drops of phenolphthalein TS: no red color develops.
• Loss on Drying 731:
Dry a sample at 105
for 4 h: it loses NMT 10.0% of its weight.
731:
Dry a sample at 105 for 4 h: it loses NMT 10.0% of its weight.
ADDITIONAL REQUIREMENTS
• Packaging and Storage:
Preserve in tight containers.
Auxiliary Information—
Please check for your question in the FAQs before contacting USP.
| Topic/Question | Contact | Expert Committee |
|---|---|---|
| Monograph | Robert H. Lafaver, M.S.
Scientific Liaison 1-301-816-8335 |
(EXC2010) Monographs - Excipients |
USP35–NF30 Page 1736
Pharmacopeial Forum: Volume No. 31(5) Page 1420