Packaging and storage— Preserve in collapsible tubes,or in other tight containers,and avoid exposure to excessive heat.

USP Reference standards á11ñ— USP Nystatin RS.

Minimum fill á755ñ: meets the requirements.

Assay— Proceed as directed for Nystatin under Antibiotics—Microbial Assays á81ñ,blending a suitable accurately weighed portion of Cream in a high-speed blender for 3to 5minutes with a sufficient accurately measured volume of dimethylformamide to give a concentration of about 400USP Nystatin Units per mL.Dilute this stock solution quantitatively with Buffer No.6to obtain a Test Dilutionhaving a concentration assumed to be equal to the median dose level of the Standard.

Expert Committee:(PA7)Pharmaceutical Analysis 7

USP28–NF23Page 1407

Phone Number:1-301-816-8335