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

USP Reference standards á11ñ— USP Tetracycline Hydrochloride RS.USP Nystatin RS.

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

Dissolution á711ñ—

Loss on drying á731ñ— Dry about 100mg of Capsule contents,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 4.0%of its weight.

Limit of 4-epianhydrotetracycline á226ñ— To a quantity of Capsule contents,equivalent to about 250mg of tetracycline hydrochloride,add 10mLof 0.1Nhydrochloric acid,and adjust with 6Nammonium hydroxide to a pHof 7.8.Transfer this solution with the aid of EDTA Bufferto a 50-mLvolumetric flask,dilute with EDTA Bufferto volume,and mix.Use this solution,without delay,as the Test Solution:not more than 3.0%is found.

Assay for tetracycline hydrochloride— Proceed with Capsules as directed in the Assayunder Tetracycline Hydrochloride Capsules.

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 1892

Phone Number:1-301-816-8335