Penicillin G Potassium
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4-Thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid,3,3-dimethyl-7-oxo-6-[(phenylacetyl)amino-],monopotassium salt,[2S-(2a,5a,6b)]-.
Monopotassium (2S,5R,6R)-3,3-dimethyl-7-oxo-6-(2-phenylacetamido)-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate [113-98-4].
»Penicillin G Potassium has a potency of not less than 1440Penicillin G Units and not more than 1680Penicillin G Units per mg.
Packaging and storage—
Preserve in tight containers.
Labeling—
Where it is intended for use in preparing injectable dosage forms,the label states that it is sterile or must be subjected to further processing during the preparation of injectable dosage forms.
Identification—
A:
Infrared Absorption á197Kñ.
B:
It responds to the flame test for Potassium á191ñ.
Crystallinity á695ñ:
meets the requirements.
pHá791ñ:
between 5.0and 7.5,in a solution containing 60mg per mL.
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.
Other requirements—
Where the label states that Penicillin G Potassium is sterile,it meets the requirements for Sterilityand Bacterial endotoxinsunder Penicillin G Potassium for Injection.Where the label states that Penicillin G Potassium must be subjected to further processing during the preparation of injectable dosage forms,it meets the requirements for Bacterial endotoxinsunder Penicillin G Potassium for Injection.
Assay—
Mobile phase—
Prepare a mixture of 0.01Mmonobasic potassium phosphate and methanol (60:40).Make adjustments if necessary (see System Suitabilityunder Chromatography á621ñ).
Resolution solution—
Prepare a solution in water containing about 0.1mg each of USP Penicillin G Potassium RSand 2-phenylacetamide per mL.
Standard preparation—
Transfer about 5mg of USP Penicillin G Potassium RS,accurately weighed,to a 50-mLvolumetric flask,add about 45mLof water,and shake to dissolve.Dilute with water to volume,and mix.This solution contains the equivalent of about 160Penicillin G Units per mL.
Assay preparation—
Transfer about 5mg of Penicillin G Potassium,accurately weighed,to a 50-mLvolumetric flask,add about 45mLof water,and shake to dissolve.Dilute with water to volume,and mix.
Chromatographic system
(see Chromatography á621ñ)—The liquid chromatograph is equipped with a 220-nm detector and a 4.6-mm ×10-cm column that contains 5-µm packing L1.The flow rate is about 1mLper minute.Chromatograph the Resolution solution,and record the peak responses as directed for Procedure:the relative retention times are about 0.8for 2-phenylacetamide and 1.0for penicillin G;and the resolution,R,between 2-phenylacetamide and penicillin Gis not less than 2.0.Chromatograph the Standard preparation,and record the peak responses as directed for Procedure:the column efficiency is not less than 1000theoretical plates;the tailing factor is not more than 2.0;and the relative standard deviation for replicate injections is not more than 2.0%.
Procedure—
Separately inject equal volumes (about 10µL)of the Standard preparationand the Assay preparationinto the chromatograph,record the chromatograms,and measure the responses for the major peaks.Calculate the potency,in Penicillin G Units per mg,of the Penicillin G Potassium taken by the formula:
(PWS/WU)(rU/rS),
in which Pis the specified potency,in Penicillin G Units per mg,of USP Penicillin G Potassium RS;WSand WUare the weights,in mg,of USP Penicillin G Potassium RSand the Penicillin G Potassium taken to prepare the Standard preparationand the Assay preparation,respectively;and rUand rSare the penicillin Gpeak responses obtained from the Assay preparationand the Standard preparation,respectively.
Auxiliary Information—
Staff Liaison:William W.Wright,Ph.D.,Scientific Fellow
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28–NF23Page 1487
Phone Number:1-301-816-8335