Packaging and storage— Preserve in light-resistant,single-dose or multiple-dose containers,preferably of Type Iglass,and store at controlled room temperature.

USP Reference standards á11ñ— USP Cyanocobalamin RS.USP Endotoxin RS.

Identification— The absorption spectrum,in the range of 300nm to 550nm,of the solution employed for measurement of absorbance in the Assayexhibits maxima at the same wavelengths as that of a similar solution of USP Cyanocobalamin RS,concomitantly measured,and the ratio A361/A550is between 3.15and 3.40.

Bacterial endotoxins á85ñ— It contains not more than 0.4USP Endotoxin Unit per µg of cyanocobalamin.

pHá791ñ: between 4.5and 7.0.

Other requirements— It meets the requirements under Injections á1ñ.

Assay— Dilute,if necessary,an accurately measured volume of Injection,equivalent to not less than 300µg of cyanocobalamin,quantitatively and stepwise with water to a concentration of about 30µg per mL.Dissolve an accurately weighed quantity of USP Cyanocobalamin RSin water,and dilute quantitatively and stepwise with water to obtain a Standard solution having a known concentration of about 30µg per mL.Concomitantly determine the absorbances of both solutions in 1-cm cells at the wavelength of maximum absorbance at about 361nm,with a suitable spectrophotometer,using water as the blank.Calculate the quantity,in µg,of C63H88CoN14O14Pin each mLof the Injection taken by the formula: in which Cis the concentration,in µg per mL,of USP Cyanocobalamin RSin the Standard solution;Vis the volume,in mL,of Injection taken;and AUand ASare the absorbances of the solution from the Injection and the Standard solution,respectively.

Expert Committee:(DSN)Dietary Supplements:Non-Botanicals

USP28–NF23Page 555

Phone Number:1-301-816-8389