» Nystatin Lozenges contain not less than 90.0 percent and not more than 125.0 percent of the labeled amount of USP Nystatin Units.
Packaging and storage Preserve in tight, light-resistant containers.
USP Reference standards 11
Disintegration 701: 90 minutes, determined as set forth under Uncoated Tablets.
pH 791: between 5.0 and 7.5, in a solution prepared by dissolving 1 Lozenge in 100 mL of water at 37 and allowing the solution to cool to room temperature.
Assay Proceed as directed for Nystatin under AntibioticsMicrobial Assays 81, blending not less than 5 Lozenges for 18 to 20 minutes in a high-speed blender jar containing 100.0 mL of water. Add 400.0 mL of dimethylformamide, and blend for an additional 10 minutes. Dilute an accurately measured volume of this solution quantitatively with a mixture of dimethylformamide and water (4:1) 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 nystatin concentration assumed to be equal to the median dose level of the Standard. [noteThe Test Dilution of the specimen and the test dilutions of the Standard contain the same amount of dimethylformamide (about 4%). ]
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USP35NF30 Page 4091Pharmacopeial Forum: Volume No. 28(1) Page 135