Microcrystalline Cellulose and Carboxymethylcellulose Sodium
»Microcrystalline Cellulose and Carboxymethylcellulose Sodium is a colloid-forming,attrited mixture of Microcrystalline Cellulose and Carboxymethylcellulose Sodium.It contains not less than 75.0percent and not more than 125.0percent of the labeled amount of carboxymethylcellulose sodium,calculated on the dried basis.The viscosity of its aqueous dispersion of percent by weight stated on the label is not less than 60.0percent and not more than 140.0percent of that stated on the label in centipoises.
Packaging and storage— Preserve in tight containers,store in a dry place,and avoid exposure to excessive heat.
Labeling— Label it to indicate the percentage content of carboxymethylcellulose sodium and the viscosity of the dispersion in water of the designated weight percentage composition.
Identification—
A: Mix 6g with 300mLof water in a blender at 18,000rpm for 5minutes:a white,opaque,dispersion is produced which does not settle on standing.
B: Add several drops of the dispersion obtained in Identificationtest Ato a solution of aluminum chloride (1in 10):each drop forms a white,opaque globule which does not disperse on standing.
C: Add 3mLof iodine TSto the dispersion obtained in Identificationtest A:no blue or purplish blue color is produced.
Viscosity á911ñ— Determine the amounts of Microcrystalline Cellulose and Carboxymethylcellulose Sodium needed to prepare 600g of a suitable dispersion,calculated on the dried basis.Transfer an accurately weighed amount of water to a 1000-mLblender bowl.Begin stirring with an 18,000rpm blender at a reduced speed obtained by adjusting the voltage to 30volts by means of a suitable transformer,and immediately add the accurately weighed portion of Microcrystalline Cellulose and Carboxymethylcellulose Sodium,taking care to avoid contacting the sides of the bowl with the powder.Continue stirring at this speed for 15seconds following the addition of the powder,then increase the transformer setting to 115volts,and mix for 2minutes,accurately timed,at 18,000rpm.Stop the blender,and lower the appropriate spindle of a suitable rotational viscosimeter into the dispersion.Thirty seconds after cessation of mixing,start the viscosimeter,and determine the viscosity using the appropriate spindle to obtain a scale reading between 10%and 90%of full-scale at a speed of 20rpm.Determine the scale reading after 30seconds of rotation,and calculate the viscosity,in centipoises,by multiplying the scale reading by the constant for the spindle used at 20rpm.
pHá791ñ: between 6.0and 8.0,determined on the dispersion prepared in the test for Viscosity.
Loss on drying á731ñ— Dry it at 105to constant weight:it loses not more than 8.0%of its weight.
Residue on ignition á281ñ: not more than 5.0%.
Assay for carboxymethylcellulose sodium— Transfer about 2g of Microcrystalline Cellulose and Carboxymethylcellulose Sodium,accurately weighed,to a glass-stoppered,250-mLconical flask.Add 75mLof glacial acetic acid,attach a condenser,and reflux for 2hours.Cool,transfer the mixture to a 250-mLbeaker with the aid of small volumes of glacial acetic acid,and titrate with 0.1Nperchloric acid in dioxane VS,determining the endpoint potentiometrically.Each mLof 0.1Nperchloric acid is equivalent to 29.6mg of carboxymethylcellulose sodium.
Auxiliary Information— Staff Liaison:Catherine Sheehan,B.Sc.,Scientist
Expert Committee:(EMC)Excipients:Monograph Content
USP28–NF23Page 2983
Phone Number:1-301-816-8262