Neomycin and Polymyxin B Sulfates,Bacitracin Zinc,and Lidocaine Ointment
»Neomycin and Polymyxin B Sulfates,Bacitracin Zinc,and Lidocaine Ointment contains the equivalent of not less than 90.0percent and not more than 130.0percent of the labeled amounts of neomycin,polymyxin B,and bacitracin,and not less than 90.0percent and not more than 110.0percent of the labeled amount of lidocaine (C14H22N2O).
Packaging and storage— Preserve in well-closed containers,preferably at controlled room temperature.
Identification—
A: It meets the requirements under Thin-Layer Chromatographic Identification Test á201BNPñ.
B: The retention time of the major peak for lidocaine in the chromatogram of theAssay preparationcorresponds to that in the chromatogram of theStandard preparation,as obtained in theAssay for lidocaine.
Minimum fill á755ñ: meets the requirements.
Water,Method Iá921ñ: not more than 0.5%,20mLof a mixture of toluene and methanol (7:3)being used in place of methanol in the titration vessel.
Assay for neomycin— Proceed with Ointment as directed in theAssay for neomycin underNeomycin and Polymyxin B Sulfates and Bacitracin Zinc Ophthalmic Ointment.
Assay for polymyxin B— Proceed with Ointment as directed in theAssay for polymyxin BunderNeomycin and Polymyxin B Sulfates and Bacitracin Zinc Ophthalmic Ointment.
Assay for bacitracin— Proceed with Ointment as directed in theAssay for bacitracin underNeomycin and Polymyxin B Sulfates and Bacitracin Zinc Ophthalmic Ointment.
Assay for lidocaine—
Mobile phase,Standard preparation,and Chromatographic system— Proceed as directed in theAssay for lidocaine underNeomycin and Polymyxin B Sulfates,Bacitracin,and Lidocaine Ointment.
Assay preparation— Using the Ointment,proceed as directed forAssay preparation in theAssay for lidocaineunderNeomycin and Polymyxin B Sulfates,Bacitracin,and Lidocaine Ointment.
Procedure— Proceed as directed forProcedure in theAssay for lidocaine underNeomycin and Polymyxin B Sulfates,Bacitracin,and Lidocaine Ointment.Calculate the quantity,in mg,of lidocaine (C14H22N2O)in the portion of Ointment taken by the formula:
100C(rU/rS),
in whichCis the concentration,in mg per mL,of USP Lidocaine RSin theStandard preparation;andrUandrSare the lidocaine peak responses obtained from theAssay preparation and theStandard preparation,respectively.
Auxiliary Information— Staff Liaison:William W.Wright,Ph.D.,Scientific Fellow
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28–NF23Page 1356
Pharmacopeial Forum:Volume No.28(4)Page 1163
Phone Number:1-301-816-8335