Corticotropin Zinc Hydroxide Injectable Suspension

Corticotropin zinc hydroxide.
Corticotropin zinc hydroxide [9050-75-3].
»Corticotropin Zinc Hydroxide Injectable Suspension is a sterile suspension of corticotropin adsorbed on zinc hydroxide.Its potency is not less than 80.0percent and not more than 125.0percent of the potency stated on the label in USP Corticotropin Units.It contains not less than 1800µg and not more than 2200µg of zinc,and not less than 604µg and not more than 776µg of anhydrous dibasic sodium phosphate,for each 40USP Corticotropin Units.
Packaging and storage— Preserve in single-dose or multiple-dose containers,preferably of Type Iglass.Store at controlled room temperature.
Labeling— Label it to indicate that it is not recommended for intravenous use and that the suspension is to be well shaken before use.The container label and the package label state the potency in USP Corticotropin Units in each mL.
Bacterial endotoxins á85ñ— It contains not more than 3.1USP Endotoxin Units per USP Corticotropin Unit.
pHá791ñ: between 7.5and 8.5,determined potentiometrically.
Zinc— Pipet a volume of the well-shaken Injectable Suspension,equivalent to about 6mg of zinc,into a 125-mLconical flask,and add 2mLof a buffer mixture containing 5.4g of ammonium chloride and 26mLof ammonium hydroxide in each 100mL.Add 10mLof water and 2drops of eriochrome black TS,and titrate with 0.005Medetate disodium VSto a clear blue endpoint.Perform a blank titration,and make any necessary correction.Each mLof 0.005Medetate disodium is equivalent to 0.327mg of Zn.
Anhydrous dibasic sodium phosphate—
Ammonium molybdate reagent— Dissolve 6.4g of ammonium molybdate in 40mLof water,and add 50mLof 10Nsulfuric acid.Mix,and dilute with water to 100mL.This solution is stable for about 2weeks.
Stannous chloride reagent— Dissolve 1g of stannous chloride in 5mLof hydrochloric acid.Just prior to use,dilute 1mLof this solution with water to 100mL.
Standard preparation— Weigh accurately about 275mg of anhydrous dibasic sodium phosphate (Na2HPO4)into a 1000-mLvolumetric flask.Dissolve in and dilute with water to volume.Dilute 10mLof this solution with water to 100mL.
Test preparation— Pipet 1mLof the well-shaken Injectable Suspension into a 25-mLvolumetric flask,add 0.1mLof 10Nsulfuric acid,mix,dilute with water to volume,and again mix.
Procedure— Into separate 100-mLvolumetric flasks pipet duplicate 10-mLportions of Test preparation,duplicate 10-mLportions of Standard preparation,and 10mLof water to provide a blank.Treat each flask as follows.Dilute the contents with water to 60mL,then add 10mLof 10Nsulfuric acid,and mix.Add 10mLof Ammonium molybdate reagent,mix,add 10mLof water,and again mix.Add slowly,with mixing,5mLof Stannous chloride reagent,dilute with water to volume,and mix.Measure the absorbances of the solutions at 10minutes,accurately timed,after the first addition of the Stannous chloride reagent,at a wavelength of 710nm,with a suitable spectrophotometer,relative to the blank.Calculate the quantity,in µg,of anhydrous dibasic sodium phosphate in the portion of Injectable Suspension taken by the formula:
25C(AU/AS),
in which Cis the concentration,in µg per mL,of Na2HPO4in the Standard preparation;and AUand ASare the absorbances of the solutions from the Test preparationand the Standard preparation,respectively.
Other requirements— It meets the requirements under Injections á1ñ.
Assay— Add sufficient 0.1Nhydrochloric acid to Injectable Suspension to effect complete solution,and using this in making the Assay preparation,proceed as directed in the Assayunder Corticotropin Injection.
Auxiliary Information— Staff Liaison:Larry N.Callahan,Ph.D.,Scientist
Expert Committee:(BNT)Biotechnology and Natural Therapeutics/Diagnostics
USP28–NF23Page 546
Phone Number:1-301-816-8385