»Nystatin is a substance,or a mixture of two or more substances,produced by the growth of Streptomyces nourseiBrown et al.(Fam.Streptomycetaceae).It has a potency of not less than 4400USP Nystatin Units per mg,or,where intended for use in the extemporaneous preparation of oral suspensions,not less than 5000USP Nystatin Units per mg.
Packaging and storage Preserve in tight,light-resistant containers.
Labeling Where packaged for use in the extemporaneous preparation of oral suspensions,the label so states.
Solution: 10µg per mL,prepared as follows.Transfer about 50mg to a glass-stoppered,100-mLvolumetric flask,add 25mLof methanol and 5mLof glacial acetic acid to dissolve the specimen,dilute with methanol to volume,and mix.Pipet 2mLof this solution into a 100-mLvolumetric flask,dilute with methanol to volume,and mix.
Ratio: the ratio (A230/A279(sh))is between 0.90and 1.25.
Suspendibility (where packaged for use in the extemporaneous preparation of oral suspensions) Transfer about 200mg,accurately weighed,to a 250-mLbeaker containing 200.0mLof water,and disperse by stirring gently with a stirring rod.Allow to stand for 2minutes,and observe the suspension:the material is in suspension,and little or no sediment is present on the bottom of the beaker.If there is any sediment,assay the undisturbed suspension as directed for nystatin under AntibioticsMicrobial Assays á81ñ,using an accurately measured volume of it blended 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:not less than 90.0%of the expected number of USP Nystatin Units is found,based on the potency obtained in the Assay.
Crystallinity (where packaged for use in the extemporaneous preparation of oral suspensions)á695ñ: meets the requirements.
pHá791ñ: between 6.0and 8.0,in a 3%aqueous suspension.
Loss on drying á731ñ Dry about 100mg,accurately weighed,in a capillary-stoppered bottle in vacuum at a pressure not exceeding 5mm of mercury at 60for 3hours:it loses not more than 5.0%of its weight.
Assay Proceed with Nystatin as directed under AntibioticsMicrobial Assays á81ñ.
Auxiliary Information Staff Liaison:William W.Wright,Ph.D.,Scientific Fellow
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28NF23Page 1407Pharmacopeial Forum:Volume No.30(1)Page 141