Change to read:
pHá791ñ:
between

5.0and 7.5,
USP28in a solution containing 60mg per mL,

except where it is labeled as containing sodium citrate it is between 6.0and 7.5.
USP28
Loss on drying á731ñ
Dry about 100mg,accurately weighed,in a capillary-stoppered bottle in vacuum at a pressure not exceeding 5mm of mercury at 60

for 3hours:it loses not more than 1.5%of its weight.
Assay
Mobile phase,Standard preparation,Resolution solution,and Chromatographic system
Proceed as directed in the
Assayunder
Penicillin G Sodium.
Assay preparation 1(where it is represented as being in a single-dose container)
Constitute Penicillin G Sodium for Injection as directed in the labeling.Withdraw all of the withdrawable contents,using a hypodermic needle and syringe,and quantitatively dilute with water to obtain a solution containing about 160Penicillin G Units per mL.
Assay preparation 2(where the label states the quantity of penicillin Gin a given volume of constituted solution)
Constitute Penicillin G Sodium for Injection as directed in the labeling.Quantitatively dilute an accurately measured volume of the constituted solution with water to obtain a solution containing about 160Penicillin G Units per mL.
Assay preparation 3(where it contains Sodium Citrate)
Transfer about 50mg of the Penicillin G Sodium for Injection,accurately weighed,to a 500-mLvolumetric flask,add about 400mLof water,and shake to dissolve.Dilute with water to volume,and mix.
Procedure
Proceed as directed for
Procedurein the
Assayunder
Penicillin G Sodium.Calculate the number of Penicillin G Units in the container or in the portion of constituted solution taken by the formula:
(L/D)(PWS/50)(rU/rS),
in which
Lis the labeled quantity of Penicillin G Units in the container or in the volume of constituted solution taken;
Dis the concentration,in Penicillin G Units per mL,of
Assay preparation 1or
Assay preparation 2,on the basis of the labeled quantity in the container or in the portion of constituted solution taken and the extent of dilution;
Pis the specified potency,in Penicillin G Units per mg,of
USP Penicillin G Potassium RS;
WSis the weight,in mg,of
USP Penicillin G Potassium RStaken to prepare the
Standard preparation;and
rUand
rSare the penicillin Gpeak responses obtained from the
Assay preparationand the
Standard preparation,respectively.Calculate the potency,in Penicillin G Units per mg,of the Penicillin G Sodium for Injection taken by the formula:
10(WS/WU)(P)(rU/rS),
in which
WSand
WUare the weights,in mg,of
USP Penicillin G Potassium RSand Penicillin G Sodium for Injection taken to prepare the
Standard preparationand
Assay preparation 3,respectively;and the other terms are as defined above.Perform the above procedure on 10containers (where it is represented as being in a single-dose container)and,if necessary,on 10containers (where the label states the quantity of penicillin Gin a given volume of constituted solution).Use the individual results to determine the
Uniformity of dosage unitsand the average thereof as the
Assayvalue.