Penicillin G Potassium for Injection
»Penicillin G Potassium for Injection is sterile Penicillin G Potassium or a sterile,dry mixture of Penicillin G Potassium with not less than 4.0percent and not more than 5.0percent of Sodium Citrate,of which not more than 0.15percent may be replaced by Citric Acid.It has a potency of not less than 90.0percent and not more than 120.0percent of the labeled number of Penicillin G Units.In addition,where it contains Sodium Citrate it has a potency of not less than 1335and not more than 1595Penicillin G Units per mg.
Constituted solution—
At the time of use,it meets the requirements for Constituted Solutionsunder Injections á1ñ.
Identification—
Prepare a solution of it containing about 12,000Penicillin G Units per mLin a solvent mixture consisting of acetone,0.1Mcitric acid,and 0.1Msodium citrate (2:1:1).Prepare a Standard solution of USP Penicillin G Potassium RScontaining about 12,000Penicillin G Units per mLin the same solvent mixture.Apply separately 20µLof each solution to a thin-layer chromatographic plate (see Chromatography á621ñ)coated with a 0.25-mm layer of chromatographic silica gel mixture.Place the plate in a suitable chromatographic chamber,and develop the chromatogram in a solvent system consisting of a mixture of toluene,dioxane,and glacial acetic acid (90:25:4)until the solvent front has moved about three-fourths of the length of the plate.Remove the plate from the chamber,mark the solvent front,and allow to air-dry.Spray the plate with starch TSfollowed by dilute iodine TS(1in 10).Penicillin Gappears as a white spot on a purple background:the RFvalue of the penicillin Gspot obtained from the test solution corresponds to that obtained from the Standard solution.
Crystallinity á695ñ:
meets the requirements.
Bacterial endotoxins á85ñ—
It contains not more than 0.01USP Endotoxin Unit per 100Penicillin G Units.
Sterility á71ñ—
It meets the requirements when tested as directed for Membrane Filtrationunder Test for Sterility of the Product to be Examined.
Change to read:
pHá791ñ:
between 
5.0and 7.5,USP28in a solution containing 60mg per mL,or,where packaged for dispensing,in the solution constituted as directed in the labeling,except where it is labeled as containing sodium citrate it is between 6.0and 8.5.USP28
Loss on drying á731ñ—
Dry about 100mg,accurately weighed,in a capillary-stoppered bottle in vacuum at 60
for 3hours:it loses not more than 1.5%of its weight.
for 3hours:it loses not more than 1.5%of its weight.
Particulate matter á788ñ:
meets the requirements for small-volume injections.
Other requirements—
It meets the requirements for Uniformity of Dosage Units á905ñ,and Labelingunder Injections á1ñ.
Assay—
Mobile phase,Standard preparation,Resolution solution,and Chromatographic system—
Proceed as directed in the Assay under Penicillin G Potassium.
Assay preparation 1
(where it is represented as being in a single-dose container)—Constitute Penicillin G Potassium 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 Potassium 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 Potassium 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 Potassium.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 Potassium 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 Potassium 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.
Auxiliary Information—
Staff Liaison:William W.Wright,Ph.D.,Scientific Fellow
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28–NF23Page 1488
Pharmacopeial Forum:Volume No.30(1)Page 154
Phone Number:1-301-816-8335