Neomycin Sulfate Cream
»Neomycin Sulfate Cream contains the equivalent of not less than 90.0percent and not more than 135.0percent of the labeled amount of neomycin.
Packaging and storage— Preserve in well-closed containers,preferably at controlled room temperature.
Thin-layer chromatographic identification test á201BNPñ: meets the requirements.
Minimum fill á755ñ: meets the requirements.
Assay— Proceed as directed under Antibiotics—Microbial Assays á81ñ,using an accurately weighed portion of Cream,equivalent to about 1.75mg of neomycin,shaken in a separator with about 50mLof ether,and extracted with four 20-mLportions of Buffer No.3.Combine the aqueous extracts,and dilute with Buffer No.3to an appropriate volume to obtain a stock solution of convenient concentration.Dilute this stock solution quantitatively and stepwise with Buffer No.3to obtain a Test Dilutionhaving a concentration assumed 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 1343
Pharmacopeial Forum:Volume No.28(4)Page 1152
Phone Number:1-301-816-8335