Packaging and storage—
Preserve in tight containers,protected from excessive heat.
Labeling—
The label states the potassium and chloride contents in terms of weight and in terms of milliequivalents.Where the Tablets are packaged in individual pouches,the label instructs the user not to open until the time of use.
Identification—
One Tablet dissolves in 100mLof water with effervescence.The collected gas responds to the test for Bicarbonate á191ñ,and the resulting solution responds to the tests for Potassium á191ñand for Chloride á191ñ.
Assay for potassium—
Assay preparation—
Transfer 10Tablets to a 2000-mLvolumetric flask,dissolve in 200mLof water,swirl until effervescence ceases,dilute with water to volume,and mix.Filter,and quantitatively dilute an accurately measured volume of the filtrate with water to obtain a solution containing 30µg of potassium per mL.Transfer 5.0mLof the resulting solution to a 100-mLvolumetric flask,add 2.0mLof sodium chloride solution (1in 5)and 1.0mLof hydrochloric acid,dilute with water to volume,and mix.
Procedure—
Proceed as directed for
Procedurein the
Assayunder
Potassium Chloride Oral Solution.Calculate the quantity,in mg,of Kin each Tablet taken by the formula:
L(C/D),
in which
Lis the labeled quantity,in mg,of potassium in each Tablet,
Cis the concentration,in µg per mL,of potassium in the
Assay preparation,and
Dis the concentration,in µg per mL,of potassium in the
Assay preparationon the basis of the labeled quantity in each Tablet and the extent of dilution.
Assay for chloride—
Transfer a number of Tablets,equivalent to about 900mg of chloride,to a 2000-mLvolumetric flask.Add about 200mLof water,swirl until effervescence ceases,dilute with water to volume,and mix.Transfer 25.0mLof this solution to a 250-mLconical flask,add 50.0mLof 0.1Nsilver nitrate VSand 15mLof nitric acid,and boil,with constant swirling,until the supernatant is colorless.Cool to room temperature,add sufficient water to make a volume of about 150mL,add 5mLof ferric ammonium sulfate TS,and titrate the excess silver nitrate with 0.1Nammonium thiocyanate VSto a permanent faint brown endpoint.Each mLof 0.1Nsilver nitrate is equivalent to 3.545mg of Cl.Calculate the quantity,in mg,of chloride (Cl)in each Tablet by dividing the total amount of chloride in the Tablets taken by the number of Tablets taken.