Potassium Chloride in Sodium Chloride Injection
»Potassium Chloride in Sodium Chloride Injection is a sterile solution of Potassium Chloride and Sodium Chloride in Water for Injection.It contains not less than 95.0percent and not more than 110.0percent of the labeled amounts of potassium (K)and chloride (Cl)and not less than 95.0percent and not more than 105.0percent of the labeled amount of sodium (Na).It contains no antimicrobial agents.
Packaging and storage— Preserve in single-dose containers,preferably of Type Ior Type IIglass,or of a suitable plastic.
Labeling— The label states the potassium,sodium,and chloride contents in terms of milliequivalents in a given volume.The label states also the total osmolar concentration in mOsmol per liter.Where the contents are less than 100mL,the label alternatively may state the total osmolar concentration in mOsmol per mL.
Identification—
A: It responds to the flame test for Sodium á191ñ.
B: To 2mLof Injection add 5mLof sodium cobaltinitrite TS:a yellow precipitate is formed immediately.If necessary,centrifuge the solution and examine the precipitate (presence of potassium).
C: It responds to the tests for Chloride á191ñ.
Bacterial endotoxins á85ñ— It contains not more than 0.5USP Endotoxin Unit per mL.
pHá791ñ: between 3.5and 6.5.
Heavy metals á231ñ— Transfer to a suitable vessel a volume,in mL,of Injection,calculated to two significant figures by the formula:
0.2/[(GKLK)+(GSLS)],
in which GKand GSare the labeled amounts,in g,of potassium chloride and sodium chloride,respectively,in each 100mLof Injection,and LKand LSare the limits,in percentage,for Heavy metalsspecified under Potassium Chlorideand Sodium Chloride,respectively.Adjust the volume by evaporation or addition of water to 25mL,as necessary:it passes the test.
Other requirements— It meets the requirements under Injections á1ñ.
Assay for potassium and sodium—
Internal standard solution— Transfer 1.04g of lithium nitrate to a 1000-mLvolumetric flask,add a suitable nonionic surfactant,then add water to volume,and mix.
Potassium stock solution— Transfer 18.64g of potassium chloride,previously dried at 105for 2hours and accurately weighed,to a 250-mLvolumetric flask,add water to volume,and mix.Each mLof this stock solution contains 39.10mg (1mEq)of potassium.
Sodium stock solution— Transfer 14.61g of sodium chloride,previously dried at 105for 2hours and accurately weighed,to a 250-mLvolumetric flask,add water to volume,and mix.
Stock standard preparation— Transfer 0.1JmLof Potassium stock solutionand 0.1J¢mLof Sodium stock solutionto a 100-mLvolumetric flask,Jand J¢being the labeled amounts,in mEq per liter,of potassium and sodium,respectively,in the Injection.Dilute with water to volume,and mix.Each mLof this solution contains 0.0391Jmg of potassium (K)and 0.02299J¢mg of sodium (Na).
Standard preparation— Transfer 5.0mLof Stock standard preparationto a 500-mLvolumetric flask,dilute with Internal standard solutionto volume,and mix.
Assay preparation— Transfer 5.0mLof Injection to a 500-mLvolumetric flask,dilute with Internal standard solutionto volume,and mix.
Procedure— Using a suitable flame photometer,adjusted to read zero with Internal standard solution,concomitantly determine the flame emission readings for the Standard preparationand the Assay preparationat the wavelengths of maximum emission for potassium,sodium,and lithium (766nm,589nm,and 671nm,respectively).Calculate the quantity,in mg,of Kin each mLof the Injection taken by the formula:
C(RU,766/RU,671)(RS,671/RS,766),
in which Cis the concentration,in mg per mL,of potassium in the Stock standard preparation,RU,766and RU,671are the emission readings at the wavelengths identified by the subscript numbers obtained from the Assay preparation,and RS,671and RS,766are the emission readings at the wavelengths identified by the subscript numbers obtained from the Standard preparation.Each mg of potassium is equivalent to 0.02558mEq of potassium.Calculate the quantity,in mg,of Na in each mLof the Injection taken by the formula:
C(RU,589/RU,671)(RS,671/RS,589),
in which Cis the concentration,in mg per mL,of sodium in the Stock standard preparation,RU,589and RU,671are the emission readings at the wavelengths identified by the subscript numbers obtained for the Assay preparation,and RS,671and RS,589are the emission readings at the wavelengths identified by the subscript numbers obtained from the Standard preparation.Each mg of sodium is equivalent to 0.04350mEq of sodium.
Assay for chloride— Transfer an accurately measured volume of Injection,equivalent to about 55mg of chloride,to a conical flask,and add 10mLof glacial acetic acid,75mLof methanol,and 3drops of eosin Y TS.Titrate,with shaking,with 0.1Nsilver nitrate VSto a pink endpoint.Each mLof 0.1Nsilver nitrate is equivalent to 3.545mg of Cl.Each mg of chloride is equivalent to 0.0282mEq of Cl.
Auxiliary Information— Staff Liaison:Karen A Russo,Ph.D.,Scientist
Expert Committee:(PA1)Pharmaceutical Analysis 1
USP28–NF23Page 1589
Pharmacopeial Forum:Volume No.27(4)Page 2774
Phone Number:1-301-816-8379