|
|
11
—
USP Penicillin G Potassium RS. USP Neomycin Sulfate RS. USP Polymyxin B Sulfate RS. USP Hydrocortisone Acetate RS.
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.
467:
meets the requirements.
81, using an accurately measured volume of Topical Suspension blended for 2 minutes in a high-speed glass blender jar with 499.0 mL of Buffer No. 1 and 1.0 mL of polysorbate 80. 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.
81, using an accurately measured volume of Topical Suspension shaken in a separator with about 50 mL of ether, and extracted with four 20-mL portions of Buffer No. 3. Combine the aqueous extracts, and dilute with Buffer No. 3 to an appropriate volume to obtain a stock solution. To an accurately measured volume of this stock solution add an accurately measured volume of penicillinase sufficient to inactivate the penicillin G therein, heat at 37
for 30 minutes, and dilute quantitatively and stepwise with Buffer No. 3 to obtain a Test Dilution having a concentration of neomycin assumed to be equal to the median dose level of the Standard.
81, using an accurately measured volume of Topical Suspension blended for 2 minutes in a high-speed glass blender jar containing 499.0 mL of Buffer No. 6 and 1.0 mL of polysorbate 80. Allow to stand for 10 minutes, and to an accurately measured volume of the aqueous phase add an accurately measured volume of penicillinase sufficient to inactivate the penicillin G therein. Heat the solution at 37 for 30 minutes, and dilute quantitatively and stepwise with Buffer No. 6 to obtain a Test Dilution having a concentration of polymyxin assumed to be equal to the median dose level of the Standard. Add to each test dilution of the Standard a quantity of USP Neomycin Sulfate RS dissolved in Buffer No. 6 to obtain the same concentration of neomycin present in the Test Dilution.