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 95.0 percent and not more than 110.0 percent of the labeled amount of acetazolamide (C4H6N4O3S2).
Packaging and storage— Preserve in Containers for Sterile Solids as described under Injections 1, preferably of Type III glass, and store at room temperature.
USP Reference standards 11
USP Acetazolamide RS Click to View Structure
USP Endotoxin RS
Completeness of solution 641 A 1.0-g portion dissolves in 10 mL of carbon dioxide–free water to yield a clear solution.
Constituted solution— At the time of use, it meets the requirements for Constituted Solutions under Injections 1.
A: Dissolve about 500 mg in 5 mL of water, add 2 drops of hydrochloric acid, and allow the mixture to stand for about 15 minutes. Filter through a fine sintered-glass funnel, wash with several small portions of water, and dry in vacuum over silica gel for 3 hours: the crystals so obtained respond to the Identification tests under Acetazolamide.
B: It responds to the tests for Sodium 191.
Bacterial endotoxins 85 It contains not more than 0.5 USP Endotoxin Unit per mg of acetazolamide.
pH 791: between 9.0 and 10.0, in a freshly prepared solution (1 in 10).
Other requirements— It meets the requirements for Sterility Tests 71, Uniformity of Dosage Units 905, and Labeling under Injections 1.
Assay— Dissolve the contents of 1 container 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 500 µg of acetazolamide per mL. Pipet 5 mL of the solution into a 250-mL volumetric flask, add 25 mL of 1 N hydrochloric acid, then add water to volume, and mix. Dissolve an accurately weighed quantity of USP Acetazolamide RS in sodium hydroxide solution (1 in 100) to obtain a Standard solution having a known concentration of about 100 µg per mL. Dilute 10.0 mL of this solution with 0.1 N hydrochloric acid to 100 mL. Concomitantly determine the absorption of both solutions at the wavelength of maximum absorbance at about 265 nm, with a suitable spectrophotometer, using 0.1 N hydrochloric acid as the blank. Calculate the quantity, in µg, of C4H6N4O3S2 in the 5.0-mL portion of the solution of Acetazolamide for Injection taken by the formula:
25C(AU / AS)
in which C is the concentration, in µg per mL, of USP Acetazolamide RS in the Standard solution; and AU and AS are the absorbances of the solution from the Acetazolamide for Injection and the Standard solution, respectively.
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