Packaging and storage— Preserve in tight containers.

Identification— Afiltered solution of finely powdered Tablets,equivalent to ammonium chloride solution (1in 10),responds to the tests for Ammonium á191ñand for Chloride á191ñ.

Disintegration á701ñ: 2hours,determined as directed for Enteric-Coated Tablets.

Limit of thiocyanate— Powder and dissolve in water a sufficient number of Tablets to make about 25mLof ammonium chloride solution (1in 10),and filter.Acidify 10mLof the solution with hydrochloric acid,and add a few drops of ferric chloride TS:no reddish orange color is produced.

Assay— Weigh and finely powder not fewer than 20Tablets.Transfer an accurately weighed portion of the powder,equivalent to about 200mg of ammonium chloride,to a 500-mL Kjeldahl flask,and add 200mLof water and 50mLof sodium hydroxide solution (2in 5).Immediately connect the flask by means of a distillation trap to a well-cooled condenser,the delivery tube of which dips into 40mLof boric acid solution (1in 25)contained in a suitable receiver.Heat to boiling,and distill about 200mL.Cool the liquid in the receiver,if necessary,then add methyl red TS,and titrate with 0.1Nsulfuric acid VS.Perform a blank determination,and make any necessary correction.Each mLof 0.1Nsulfuric acid is equivalent to 5.349mg of NH4Cl.

Expert Committee:(PA4)Pharmaceutical Analysis 4

USP28–NF23Page 138

Phone Number:1-301-816-8251