Nystatin, Neomycin Sulfate, Gramicidin, and Triamcinolone Acetonide Cream
» Nystatin, Neomycin Sulfate, Gramicidin, and Triamcinolone Acetonide Cream contains not less than 90.0 percent and not more than 140.0 percent of the labeled amounts of nystatin, neomycin, and gramicidin, and not less than 90.0 percent and not more than 110.0 percent of the labeled amount of triamcinolone acetonide (C24H31FO6).
Packaging and storage Preserve in tight containers.
USP Reference standards 11
USP Gramicidin RS
USP Neomycin Sulfate RS
Identification Place 2 g of Cream in a conical flask, add 5.0 mL of chloroform, and shake for 10 minutes. Add 15 mL of alcohol, and shake for an additional 10 minutes. Filter the solution into a centrifuge tube, and evaporate the filtrate to dryness. Dissolve the residue in alcohol to obtain a solution containing about 250 µg of triamcinolone acetonide per mL. Proceed as directed in the Identification test under Triamcinolone Acetonide Cream, beginning with Apply 10 µL of this solution: the specified result is observed.
Minimum fill 755: meets the requirements.
Assay for nystatin Proceed as directed for nystatin under AntibioticsMicrobial Assays 81, blending a suitable, accurately weighed portion of Cream in a high-speed blender for 3 to 5 minutes with a sufficient, accurately measured volume of dimethylformamide to give a convenient concentration. Dilute an accurately measured volume of the solution so obtained quantitatively with dimethylformamide to obtain a stock solution containing about 400 USP Nystatin Units per mL. Dilute an accurately measured volume of this stock solution quantitatively with Buffer No. 6 to obtain a Test Dilution having a concentration of nystatin assumed to be equal to the median dose level of the Standard.
Assay for gramicidin Proceed as directed for gramicidin under AntibioticsMicrobial Assays 81, using an accurately weighed portion of Cream dissolved in 50 mL of hexanes in a separator, and extracted with four 20-mL portions of 80% alcohol. Combine the extracts in a suitable volumetric flask, dilute with alcohol to volume, and mix. Dilute an accurately measured volume of the solution so obtained quantitatively and stepwise with alcohol to obtain a Test Dilution having a concentration of gramicidin assumed to be equal to the median dose level of the Standard.
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USP35NF30 Page 4093