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

USP Reference standards á11ñ— USP Oxytetracycline RS.USP Nystatin RS

Identification— Shake a suitable quantity of Capsule contents with methanol to obtain a solution containing about 1mg of oxytetracycline per mL,and filter.Using the filtrate as the Test Solution,proceed as directed for Method IIunder Identification—Tetracyclines á193ñ.

Dissolution á711ñ—

Uniformity of dosage units á905ñ: meet the requirements for Weight Variationwith respect to oxytetracycline.

Water,Method Iá921ñ: not more than 7.5%.

Assay for oxytetracycline— Place not less than 5Capsules in a high-speed glass blender jar containing an accurately measured volume of 0.1Nhydrochloric acid,and blend for 3to 5minutes,so that the stock solution so obtained contains not less than 150µg of oxytetracycline (C22H24N2O9)per mL.Proceed as directed under Antibiotics—Microbial Assays á81ñ,using an accurately measured volume of this stock solution diluted quantitatively and stepwise with water to yield a Test Dilutionhaving a concentration of oxytetracycline assumed to be equal to the median dose level of the Standard.

Assay for nystatin— Proceed as directed for Nystatin under Antibiotics—Microbial Assays á81ñ,blending not less than 5Capsules for 3to 5minutes in a high-speed blender with a sufficient accurately measured volume of dimethylformamide to obtain a solution of convenient concentration.Dilute an accurately measured portion of this solution quantitatively with dimethylformamide to obtain a stock solution containing about 400USP Nystatin Units per mL.Dilute this stock solution quantitatively with Buffer No.6to obtain a Test Dilutionhaving a concentration of nystatin assumed to be equal to the median dose level of the Standard.

Expert Committee:(PA7)Pharmaceutical Analysis 7

USP28–NF23Page 1449

Phone Number:1-301-816-8335