C44H46CaN4O18 958.93

2-Naphthacenecarboxamide,4-(dimethylamino)-1,4,4a,5,5a,6,11,12a-octahydro-3,5,6,10,12,12a-hexahydroxy-6-methyl-1,11-dioxo-,calcium salt,[4S-(4a,4aa,5a,5aa,6b,12aa)]-.
4-(Dimethylamino)-1,4,4a,5,5a,6,11,12a-octahydro-3,5,6,10,12,12a-hexahydroxy-6-methyl-1,11-dioxo 2-naphthacenecarboxamide calcium salt [15251-48-6].

Packaging and storage— Preserve in tight,light-resistant containers,and store in a cool place.

USP Reference standards á11ñ— USP Oxytetracycline RS.

Identification— Dissolve a suitable quantity in methanol to obtain a Test Solutioncontaining 1mg of oxytetracycline per mL,and proceed as directed for Method IIunder Identification—Tetracyclines á193ñ.

Crystallinity á695ñ: meets the requirements.

pHá791ñ: between 6.0and 8.0,in an aqueous suspension containing 25mg per mL.

Water,Method Iá921ñ: between 8.0%and 14.0%.

Calcium content— Proceed as directed under Residue on Ignition á281ñ,except to ignite at 550±50instead of at 800±25:the weight of residue so obtained,multiplied by 0.2944,gives the equivalent of calcium in the Oxytetracycline Calcium taken.The calcium content is between 3.85%and 4.35%,calculated on the anhydrous basis.

Assay— Dissolve an accurately weighed quantity of Oxytetracycline Calcium in an accurately measured volume of 0.1Nhydrochloric acid to obtain a stock solution having a concentration of about 1000µg of oxytetracycline per mL.Proceed as directed for oxytetracycline under Antibiotics—Microbial á81ñ,using an accurately measured volume of the stock solution diluted quantitatively and stepwise with water to yield 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 1450

Phone Number:1-301-816-8335