Hydroxocobalamin Injection
»Hydroxocobalamin Injection is a sterile solution of Hydroxocobalamin in Water for Injection.It contains not less than 95.0percent and not more than 115.0percent of the labeled amount of hydroxocobalamin (C62H89CoN13O15P).
Packaging and storage— Preserve in single-dose or in multiple-dose containers,preferably of Type Iglass,protected from light.
Identification— Dilute 3.0mLof Injection with pH4.0buffer (prepared by dissolving 2.61g of sodium acetate and 20.5g of sodium chloride in 5.25mLof glacial acetic acid and sufficient water to make 1500mLof solution)to 100mL:the UV-visible absorption spectrum of this solution exhibits maxima at 352±2nm and 525±2nm.The ratio A352/A525is between 2.7and 3.3.
Bacterial endotoxins á85ñ— It contains not more than 0.4USP Endotoxin Unit per µg of hydroxocobalamin.
pHá791ñ: between 3.5and 5.0.
Other requirements— It meets the requirements under Injections á1ñ.
Assay—
pH9.3Buffer— Dissolve 23.8g of sodium borate and 402mg of boric acid in sufficient water to make 1500mLof solution,and mix.
Standard preparation— Dissolve a suitable quantity of USP Cyanocobalamin RS,accurately weighed,in pH9.3Bufferand dilute quantitatively,and stepwise if necessary,to obtain a solution having a known concentration of about 30µg per mL.
Assay preparation— Transfer an accurately measured volume of Injection,equivalent to about 5mg of hydroxocobalamin,to a 50-mLvolumetric flask containing about 25mLof pH9.3Buffer.Add 5.0mLof potassium cyanide solution (1in 10,000),allow to stand at room temperature for 30minutes,dilute with pH9.3Bufferto volume,and mix.Transfer 15.0mLof this solution to a second 50-mLvolumetric flask,dilute with pH9.3Bufferto volume,and mix.
Procedure— Concomitantly determine the absorbances of the solutions in 1-cm cells at the wavelength of maximum absorbance at about 361nm,with a suitable spectrophotometer,using pH9.3Bufferas the blank.Calculate the quantity,in mg,of hydroxocobalamin (C62H89CoN13O15P)in each mLof the Injection taken by the formula:
(1346.36/1355.37)(0.1667C/V)(AU/AS),
in which 1346.36and 1355.37are the molecular weights of hydroxocobalamin and cyanocobalamin,respectively;Cis the concentration,in µg per mL,of USP Cyanocobalamin RSin the Standard preparation;Vis the volume,in mL,of Injection taken;and AUand ASare the absorbances of the Assay preparationand the Standard preparation,respectively.
Auxiliary Information— Staff Liaison:Andrzej Wilk,Ph.D.,Senior Scientific Associate
Expert Committee:(PA5)Pharmaceutical Analysis 5
USP28–NF23Page 976
Phone Number:1-301-816-8305