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11
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USP Bacitracin Zinc RS. USP Neomycin Sulfate RS. USP Polymyxin B Sulfate RS.
201BNP:
meets the requirements.
71:
meets the requirements.
755:
meets the requirements.
921:
not more than 0.5%, 20 mL of a mixture of toluene and methanol (7:3) being used in place of methanol in the titration vessel.
751.
467:
meets the requirements.
81, using an accurately weighed portion of Ophthalmic Ointment 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. Dilute this stock solution quantitatively and stepwise with Buffer No. 3 to obtain a Test Dilution having a concentration assumed to be equal to the median dose level of the Standard.
81, using an accurately weighed portion of Ophthalmic Ointment shaken with about 50 mL of ether in a separator, and extracted with four 25-mL portions of Buffer No. 6. Combine the aqueous extracts, and dilute with Buffer No. 6 to an appropriate volume to obtain a stock solution. Dilute this stock solution quantitatively and stepwise with Buffer No. 6 to obtain a Test Dilution having a concentration assumed to be equal to the median dose level of the Standard (10 Polymyxin B Units per mL). Add to each test dilution of the Standard a quantity of Neomycin Standard, dissolved in Buffer No. 6, to obtain the same concentration of neomycin present in the Test Dilution.
81, using an accurately weighed portion of Ophthalmic Ointment shaken with about 50 mL of ether in a separator, and extracted with four 25-mL portions of 0.01 N hydrochloric acid. Combine the acid extracts, and dilute with 0.01 N hydrochloric acid to an appropriate volume to obtain a stock solution. Dilute this stock solution quantitatively and stepwise with Buffer No. 1 to obtain a Test Dilution having a concentration assumed to be equal to the median dose level of the Standard (1.0 Bacitracin Unit per mL). [NOTE—If the stock solution has a concentration of less than 100 Bacitracin Units per mL, add additional hydrochloric acid to each test dilution of the Standard to obtain the same concentration of hydrochloric acid as the Test Dilution.]