Packaging and storage—
Preserve in tight containers.
Identification—
Digest a quantity of powdered Tablets, equivalent to about 1 g of carboxymethylcellulose sodium, with 50 mL of water until solution is virtually complete, and filter: the filtrate responds to the following tests.
A:
To about 30 mL of the solution add 3 mL of hydrochloric acid: a white precipitate is formed.
B:
To the remainder of the solution add an equal volume of
barium chloride TS: a fine, white precipitate is formed.
C:
The filtrate from
Identification test
A responds to the tests for
Sodium 
191
.
Assay—
Weigh and finely powder not less than 20 Tablets. Weigh accurately a portion of the powder, equivalent to about 500 mg of carboxymethylcellulose sodium, add 80 mL of glacial acetic acid, heat the mixture on a steam bath for 2 hours, cool to room temperature, and titrate with 0.1 N perchloric acid VS, determining the endpoint potentiometrically. Each mL of 0.1 N perchloric acid is equivalent to 2.299 mg of Na.
