Packaging and storage— Preserve in tight,light-resistant containers.

USP Reference standards á11ñ— USP Nystatin RS.

Disintegration á701ñ: 90minutes,determined as set forth under Uncoated Tablets.

pHá791ñ: between 5.0and 7.5,in a solution prepared by dissolving 1Lozenge in 100mLof water at 37and allowing the solution to cool to room temperature.

Assay— Proceed as directed for Nystatin under Antibiotics—Microbial Assays á81ñ,blending not less than 5Lozenges for 18to 20minutes in a high-speed blender jar containing 100.0mLof water.Add 400.0mLof dimethylformamide,and blend for an additional 10minutes.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 400USP Nystatin Units per mL.Dilute an accurately measured volume of this stock solution quantitatively with Buffer No.6to obtain a Test Dilutionhaving a nystatin concentration assumed to be equal to the median dose level of the Standard.[NOTE—The Test Dilution of the specimen and the test dilutions of the Standard contain the same amount of dimethylformamide (about 4%).]

Expert Committee:(PA7)Pharmaceutical Analysis 7

USP28–NF23Page 1407

Phone Number:1-301-816-8335