Penicillin G Procaine and Novobiocin Sodium Intramammary Infusion
»Penicillin G Procaine and Novobiocin Sodium Intramammary Infusion is a suspension of Penicillin G Procaine and Novobiocin Sodium in a suitable vegetable oil vehicle.It contains a suitable preservative and suspending agent.It contains not less than 90.0percent and not more than 125.0percent of the labeled amounts of Penicillin G Units and novobiocin (C31H36N2O11).
Packaging and storage—
Preserve in disposable syringes that are well-closed containers.
Labeling—
Label it to indicate that it is for veterinary use only.
Water,Method Iá921ñ:
not more than 1.0%,20mLof a mixture of toluene and methanol (7:3)being used in place of methanol in the titration vessel.
Assay for penicillin G—
Proceed as directed for penicillin Gunder Antibiotics—Microbial Assays á81ñ,except to use Staphylococcus aureusATCC No.12692as the test organism.Prepare the inoculum by growing the organism at 32
to 35for 24hours on Medium 1to which has been added a solution of novobiocin sodium,containing the equivalent of 2.5mg of novobiocin per mLthat has been filtered through a membrane filter having a 0.2-µm porosity,so that the medium contains the equivalent of 10µg of novobiocin per mL.Use an inoculum composition of about 5mLof stock suspension in each 100mLof Medium 1.Expel the contents of a syringe of Intramammary Infusion into a high-speed glass blender jar containing 1.0mLof polysorbate 80and 499.0mLof Buffer No.1,and blend for 3to 5minutes.Allow to stand for 10minutes,and dilute an accurately measured volume of the aqueous phase quantitatively and stepwise with Buffer No.1to obtain a Test Dilutionhaving a concentration of penicillin Gassumed to be equal to the median dose level of the Standard.
to 35for 24hours on Medium 1to which has been added a solution of novobiocin sodium,containing the equivalent of 2.5mg of novobiocin per mLthat has been filtered through a membrane filter having a 0.2-µm porosity,so that the medium contains the equivalent of 10µg of novobiocin per mL.Use an inoculum composition of about 5mLof stock suspension in each 100mLof Medium 1.Expel the contents of a syringe of Intramammary Infusion into a high-speed glass blender jar containing 1.0mLof polysorbate 80and 499.0mLof Buffer No.1,and blend for 3to 5minutes.Allow to stand for 10minutes,and dilute an accurately measured volume of the aqueous phase quantitatively and stepwise with Buffer No.1to obtain a Test Dilutionhaving a concentration of penicillin Gassumed to be equal to the median dose level of the Standard.
Assay for novobiocin—
Proceed as directed for novobiocin under Antibiotics—Microbial Assays á81ñ,expelling the contents of a syringe of Intramammary Infusion into a high-speed blender jar containing 1.0mLof polysorbate 80and 499.0mLof Buffer No.3,and blend for 3to 5minutes.Allow to stand for 10minutes.To an accurately measured volume of the aqueous phase add sufficient penicillinase to inactivate the penicillin Gtherein,and dilute quantitatively and stepwise with Buffer No.6to obtain a Test Dilutionhaving a concentration of novobiocin assumed to be equal to the median dose level of the Standard.[NOTE—Store this Test Dilution at 37for 30minutes and allow to cool before using it to fill the cylinders on the plates.]
for 30minutes and allow to cool before using it to fill the cylinders on the plates.]
Auxiliary Information—
Staff Liaison:Ian DeVeau,Ph.D.,Senior Scientist
Expert Committee:(VET)Veterinary Drugs
USP28–NF23Page 1495
Phone Number:1-301-816-8178