Packaging and storage— Preserve in tight containers.

Identification— It responds to the tests for Chloride á191ñ.

Residue on ignition á281ñ— To 20mLadd 2drops of sulfuric acid,evaporate to dryness,and ignite:the weight of the residue does not exceed 2mg.

Sulfate— To a mixture of 3mLof it and 5mLof water add 5drops of barium chloride TS:neither turbidity nor precipitate appears within 1hour.

Sulfite— On the completion of the test for Sulfate,the further addition to the liquid of 2drops of 0.1Niodine produces neither turbidity nor decolorization of the iodine.

Heavy metals á231ñ— To 3.8mL(4g)add 5mLof water and 1drop of phenolphthalein TS.Add 6Nammonium hydroxide until the solution assumes a faint pink color.Add 2mLof 1Nacetic acid,then add water to make 25mL:the limit is 5ppm.

Free bromine or chlorine— To 10mLadd 1mLof potassium iodide TSand 1mLof chloroform,and agitate the mixture:the chloroform remains free from any violet coloration for at least 1minute.

Assay— Transfer 10.0mLof Diluted Hydrochloric Acid to a conical flask,and add about 20mLof water.Add 3drops of methyl red TS,and titrate with 1Nsodium hydroxide VS.Each mLof 1Nsodium hydroxide is equivalent to 36.46mg of HCl.

Expert Committee:(EMC)Excipients:Monograph Content

USP28–NF23Page 3017

Phone Number:1-301-816-8379