C7H5NaO2 144.10

Benzoic acid,sodium salt.
Sodium benzoate [532-32-1].

Packaging and storage— Preserve in well-closed containers.

Identification— It responds to the tests for Sodium á191ñand for Benzoate á191ñ.

Alkalinity— Dissolve 2g in 20mLof hot water,and add 2drops of phenolphthalein TS:the pink color produced,if any,is discharged by the addition of 0.20mLof 0.10Nsulfuric acid.

Water,Method Iá921ñ: not more than 1.5%.

Heavy metals á231ñ— Dissolve 4.0g in 40mLof water,add,dropwise,with vigorous stirring,10mLof 3Nhydrochloric acid,and filter.Use 25mLof the filtrate:the limit is 0.001%.

Organic volatile impurities,Method IVá467ñ: meets the requirements.

Assay— Transfer about 600mg of Sodium Benzoate,accurately weighed,to a 250-mLbeaker.Add 100mLof glacial acetic acid,stir until the assay specimen is completely dissolved,add 2drops of crystal violet TS,and titrate with 0.1Nperchloric acid VSto a green endpoint.Perform a blank determination,and make any necessary correction.Each mLof 0.1Nperchloric acid is equivalent to 14.41mg of C7H5NaO2.

Expert Committee:(EMC)Excipients:Monograph Content

USP28–NF23Page 3075

Phone Number:1-301-816-8330