Cellulose,carboxymethyl ether,calcium salt.
Cellulose carboxymethyl ether calcium salt [9050-04-8].

Packaging and storage— Preserve in tight containers.

Identification—

Alkalinity— Shake thoroughly 1.0g with 50mLof freshly boiled and cooled water,and add 2drops of phenolphthalein TS:no red color develops.

Loss on drying á731ñ— Dry it at 105ºfor 4hours:it loses not more than 10.0%of its weight.

Residue on ignition á281ñ: between 10.0%and 20.0%,about 1.0g,previously dried,being used for the test.

Heavy metals á231ñ— Determine as directed in the test forHeavy metalsunderMethylcellulose,except to use only 1g of Carboxymethylcellulose Calcium.The limit is 0.002%.

Limit of chloride á221ñ— Shake thoroughly 0.80g with 50mLof water,dissolve in 10mLof 1Nsodium hydroxide,add water to make 100mL,and use 20mLof this solution as the test solution,retaining the remainder of it for the test forLimit of sulfate.Heat 20mLof the test solution with 10mLof 2Nnitric acid in a water bath until a flocculent precipitate is formed,cool,centrifuge,and remove the supernatant.Wash the precipitate with three 10-mLportions of water by centrifuging each time,combine the supernatant and the washings,add water to make 100mL,and mix:a 25-mLportion of this solution shows no more chloride than is contained in 0.20mLof 0.020Nhydrochloric acid (0.36%).

Limit of sulfate á221ñ— Heat 10mLof the test solution obtained in test forLimit of chloride with 1mLof hydrochloric acid in a water bath until a flocculent precipitate is formed,cool,centrifuge,and remove the supernatant.Wash the precipitate with three 10-mLportions of water by centrifuging each time,combine the supernatant and the washings,add water to make 100mL,and mix:a 25-mLportion of this solution shows no more sulfate than is contained in 0.21mLof 0.020Nsulfuric acid (1.0%).NF23

Expert Committee:(EMC)Excipients:Monograph Content

USP28–NF23Page 2976

Phone Number:1-301-816-8323