Starch carboxymethyl ether,sodium salt.

Packaging and storage— Preserve in well-closed containers,preferably protected from wide variations in temperature and humidity,which may cause caking.

Labeling— The labeling indicates the pHrange.

Identification— Aslightly acidified solution of it is colored blue by iodine and potassium iodide TS.

Microbial limits á61ñ— It meets the requirements of the tests for absence of Salmonellaspecies and Escherichia coli.

pHá791ñ— Disperse 1g in 30mLof water:the pHof the resulting suspension is either between 3.0and 5.0or between 5.5and 7.5.

Loss on drying á731ñ— Dry it at 130for 90minutes:it loses not more than 10.0%of its weight.

Iron á241ñ: 0.002%,the Test Preparationbeing prepared as directed for Test Preparationunder Heavy metals,Method IIIá231ñ,a 0.5-g test specimen being used and the final solution being diluted with water to 47mL.

Heavy metals,Method IIá231ñ: 0.002%.

Sodium chloride— Weigh accurately about 1g,transfer to a conical flask,add 20mLof 80%alcohol,0.1mLof phenolphthalein TS,and 1Nsodium hydroxide solution until the suspension becomes faintly pink,stir for 10minutes,and filter.Repeat the extraction until chloride has been completely extracted,as shown by a test with silver nitrate TS.Dry the insoluble portion at 105to constant weight (Amg),and reserve it for the Assay.Evaporate the combined filtrates,and dry the residue at 105to constant weight.The weight of the dried residue is not greater than 15%of the weight of Sodium Starch Glycolate taken.If the weight of the dried residue is not more than 7.0%of the weight of Sodium Starch Glycolate taken,the requirement is met.If the weight is greater than 7.0%of the weight of Sodium Starch Glycolate taken,transfer it with the aid of water to a 200-mLvolumetric flask,add 5mLof nitric acid and 40.0mLof 0.1Nsilver nitrate VS,mix,and dilute with water to volume.Allow it to stand in the dark for 30minutes,and filter.To 100.0mLof the filtrate add 5mLof ferric ammonium sulfate TS,and titrate with 0.1Nammonium thiocyanate VS(see Residual Titrationsunder Titrimetry á541ñ).Calculate the percentage of sodium chloride by the formula: in which N1and N2are the normalities of the silver nitrate VSand the ammonium thiocyanate VS,respectively;Vis the volume,in mL,of ammonium thiocyanate VSused in the titration;and Wis the weight,in g,of Sodium Starch Glycolate taken.

Assay— Transfer an accurately weighed portion,B,(about 700mg)of the dried 80%alcohol-insoluble portion obtained in the test for Sodium chloride,to a suitable flask,add 80mLof glacial acetic acid,heat the mixture under reflux,on a boiling water bath,for 2hours,cool to room temperature,and titrate with 0.1Nperchloric acid VS,determining the endpoint potentiometrically.Calculate the percentage of sodium combined in the form of sodium starch glycolate by the formula: in which V3is the volume,in mL,of the perchloric acid VS;N3is the normality of the perchloric acid VS;and Bis the weight,in mg,of the dried alcohol-insoluble residue taken for the Assay.

Expert Committee:(EMC)Excipients:Monograph Content

USP28–NF23Page 3080

Phone Number:1-301-816-8323