Acetazolamide for Injection
»Acetazolamide for Injection is prepared from Acetazolamide with the aid of Sodium Hydroxide.It is suitable for parenteral use.The contents of each container,when constituted as directed in the labeling,yield a solution containing not less than 95.0percent and not more than 110.0percent of the labeled amount of acetazolamide (C4H6N4O3S2).
Packaging and storage— Preserve in Containers for Sterile Solidsas described under Injections á1ñ,preferably of Type IIIglass,and store at room temperature.
Completeness of solution á641ñ— A1.0-g portion dissolves in 10mLof carbon dioxide–free water to yield a clear solution.
Constituted solution— At the time of use,it meets the requirements for Constituted Solutionsunder Injections á1ñ.
Identification—
A: Dissolve about 500mg in 5mLof water,add 2drops of hydrochloric acid,and allow the mixture to stand for about 15minutes.Filter through a fine sintered-glass funnel,wash with several small portions of water,and dry in vacuum over silica gel for 3hours:the crystals so obtained respond to the Identificationtests under Acetazolamide.
B: It responds to the tests for Sodium á191ñ.
Bacterial endotoxins á85ñ— It contains not more than 0.5USP Endotoxin Unit per mg of acetazolamide.
pHá791ñ: between 9.0and 10.0,in a freshly prepared solution (1in 10).
Other requirements— It meets the requirements for Sterility Tests á71ñ,Uniformity of Dosage Units á905ñ,and Labelingunder Injections á1ñ.
Assay— Dissolve the contents of 1container of Acetazolamide for Injection in an accurately measured volume of water corresponding to the volume of solvent specified in the labeling.Dilute a portion of the solution quantitatively and stepwise with water to obtain a solution having a concentration of about 500µg of acetazolamide per mL.Pipet 5mLof the solution into a 250-mLvolumetric flask,add 25mLof 1Nhydrochloric acid,then add water to volume,and mix.Dissolve an accurately weighed quantity of USP Acetazolamide RSin sodium hydroxide solution (1in 100)to obtain a Standard solution having a known concentration of about 100µg per mL.Dilute 10.0mLof this solution with 0.1Nhydrochloric acid to 100mL.Concomitantly determine the absorption of both solutions at the wavelength of maximum absorbance at about 265nm,with a suitable spectrophotometer,using 0.1Nhydrochloric acid as the blank.Calculate the quantity,in µg,of C4H6N4O3S2in the 5.0-mLportion of the solution of Acetazolamide for Injection taken by the formula:
25C(AU/AS),
in which Cis the concentration,in µg per mL,of USP Acetazolamide RSin the Standard solution;and AUand ASare the absorbances of the solution from the Acetazolamide for Injection and the Standard solution,respectively.
Auxiliary Information— Staff Liaison:Lawrence Evans,III,Ph.D.,Scientist
Expert Committee:(PA6)Pharmaceutical Analysis 6
USP28–NF23Page 42
Pharmacopeial Forum:Volume No.27(3)Page 2500
Phone Number:1-301-816-8389