Bacitracin and Polymyxin B Sulfate Topical Aerosol
»Bacitracin and Polymyxin B Sulfate Topical Aerosol is a suspension of Bacitracin and Polymyxin B Sulfate in a suitable vehicle,packaged in a pressurized container with a suitable inert propellant.It contains not less than 90.0percent and not more than 130.0percent of the labeled amounts of bacitracin and polymyxin B.It may contain a suitable local anesthetic.
Packaging and storage—
Preserve in pressurized containers,and avoid exposure to excessive heat.
USP Reference standards á11ñ—
USP Bacitracin Zinc RS.USP Polymyxin B Sulfate RS.
NOTE—Prepare the specimen for the following tests and assays as follows.Maintain the container in the inverted position throughout this procedure.Store the container in a freezer at -70
for 16to 24hours.Remove the container from the freezer,promptly puncture the container,and allow the propellant to volatilize.Open the container,and mix the contents.
for 16to 24hours.Remove the container from the freezer,promptly puncture the container,and allow the propellant to volatilize.Open the container,and mix the contents.
Thin-layer chromatographic identification test á201BNPñ—
Aportion of the contents of 1container prepared as directed above and tested as directed for Creams,Lotions,and Ointmentsmeets the requirements.
Water,Method Iá921ñ:
not more than 0.5%,an accurately weighed portion of the contents of 1container,prepared as directed above,being used,and 20mLof a mixture of toluene and methanol (7:3)being used in place of methanol in the titration vessel.
Other requirements—
It meets the requirements for Pressure Test,Minimum Fill,and Leakage Testunder Aerosols,Nasal Sprays,Metered-Dose Inhalers,and Dry Powder Inhalers á601ñ.
Assay for bacitracin—
Proceed as directed for bacitracin under Antibiotics—Microbial Assays á81ñ,using an accurately weighed portion of the contents of 1container,prepared as directed above,equivalent to about 500USP Bacitracin Units.Transfer to a suitable separator containing about 50mLof ether,and extract with three 25-mLportions of Buffer No.1.Combine the buffer extracts in a 100-mLvolumetric flask,dilute with Buffer No.1to volume,and mix.Add sufficient 0.01Nhydrochloric acid to an accurately measured volume of this solution so that the amount of hydrochloric acid in the Test Dilutionwill be the same as in the median dose level of the Standard,and quantitatively dilute with Buffer No.1to obtain a Test Dilutionhaving a bacitracin concentration assumed to be equal to the median dose level of the Standard.
Assay for polymyxin B—
Proceed as directed for polymyxin Bunder Antibiotics—Microbial Assays á81ñTransfer an accurately weighed portion of the contents of 1container,prepared as directed above,equivalent to about 5000USP Polymyxin B Units,to a suitable separator containing about 50mLof ether,and extract with three 25-mLportions of Buffer No.6.Combine the buffer extracts in a 100-mLvolumetric flask,dilute with Buffer No.6to volume,and mix.Dilute an accurately measured volume of this solution,quantitatively and stepwise,with Buffer No.6to obtain a Test Dilutionhaving a concentration of polymyxin Bassumed to be equal to the median dose level of the Standard.
Auxiliary Information—
Staff Liaison:William W.Wright,Ph.D.,Scientific Fellow
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28–NF23Page 215
Pharmacopeial Forum:Volume No.28(4)Page 1070
Phone Number:1-301-816-8335