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 90.0 percent and not more than 125.0 percent 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 I 921 :
not more than 1.0%, 20 mL of 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 G under AntibioticsMicrobial Assays 81 , except to use Staphylococcus aureus ATCC No. 12692 as the test organism. Prepare the inoculum by growing the organism at 32 to 35 for 24 hours on Medium 1 to which has been added a solution of novobiocin sodium, containing the equivalent of 2.5 mg of novobiocin per mL that has been filtered through a membrane filter having a 0.2-µm porosity, so that the medium contains the equivalent of 10 µg of novobiocin per mL. Use an inoculum composition of about 5 mL of stock suspension in each 100 mL of Medium 1. Expel the contents of a syringe of Intramammary Infusion into a high-speed glass blender jar containing 1.0 mL of polysorbate 80 and 499.0 mL of Buffer No. 1, and blend for 3 to 5 minutes. Allow to stand for 10 minutes, and dilute an accurately measured volume of the aqueous phase quantitatively and stepwise with Buffer No. 1 to obtain a Test Dilution having a concentration of penicillin G assumed to be equal to the median dose level of the Standard.
Assay for novobiocin
Proceed as directed for novobiocin under AntibioticsMicrobial Assays 81 , expelling the contents of a syringe of Intramammary Infusion into a high-speed blender jar containing 1.0 mL of polysorbate 80 and 499.0 mL of Buffer No. 3, and blend for 3 to 5 minutes. Allow to stand for 10 minutes. To an accurately measured volume of the aqueous phase add sufficient penicillinase to inactivate the penicillin G therein, and dilute quantitatively and stepwise with Buffer No. 6 to obtain a Test Dilution having a concentration of novobiocin assumed to be equal to the median dose level of the Standard. [noteStore this Test Dilution at 37 for 30 minutes and allow to cool before using it to fill the cylinders on the plates. ]
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