Acetazolamide Oral Suspension
Acetazolamide Oral Suspension contains NLT 90.0% and NMT 110.0% of the labeled amount of acetazolamide (C4H6N4O3S2).
Prepare Acetazolamide Oral Suspension, 25 mg/mL, as follows (see Pharmaceutical CompoundingNonsterile Preparations 795; see also Acetazolamide Oral Solution).
[NoteIf tablets are used instead of bulk powder, the preparation becomes a suspension and should be labeled as such. ]
If using tablets, place in a mortar and comminute to a fine powder, or add Acetazolamide powder. Add about 20 mL of the Vehicle, and mix to a uniform paste. Add the Vehicle in small portions almost to volume, and mix thoroughly after each addition. Transfer the contents of the mortar, stepwise and quantitatively, to a calibrated bottle. Add enough liquid Vehicle to bring to final volume, and mix well.
Mobile phase: Dissolve 4.1 g of anhydrous sodium acetate in 950 mL of water, and add 20 mL of methanol and 30 mL of acetonitrile. Adjust with glacial acetic acid to a pH of 4.0.
Standard stock solution: Transfer about 25 mg of USP Acetazolamide RS, accurately weighed, to a 50-mL volumetric flask, add 5.0 mL of 0.5 N sodium hydroxide, and mix to dissolve. Dilute with water to volume, and mix.
Standard solution: 250 µg/mL from the Standard stock solution in water
Sample solution: 250 µg/mL of acetazolamide from Oral Suspension in Mobile phase. Agitate the container of Oral Suspension for 30 min on a rotating mixer, remove a 5-mL sample, and store in a clear glass vial at 70 until analyzed. At the time of analysis, remove the sample from the freezer, allow to reach room temperature, and mix with a vortex mixer for 30 s. Pipet 1.0 mL of this solution to a 100-mL volumetric flask, and dilute with Mobile phase to volume.
Detector: UV 254 nm
Column: 4.6-mm × 25-cm; 5-µm packing L1
Flow rate: 2 mL/min
Injection size: 20 µL
Sample: Standard solution
[NoteThe retention time for the acetazolamide peak is about 3 min. ]
Relative standard deviation: NMT 1.1% for replicate injections
Samples: Standard solution and Sample solution
Calculate the percentage of the labeled amount of acetazolamide (C4H6N4O3S2) in the portion of Oral Suspension taken:
Result = (rU/rS) × (CS/CU) × 100
Acceptance criteria: 90.0%110.0%
• pH 791: 4.05.0 (Vehicle for Oral Solution and Vehicle for Oral Suspension), 3.13.9 (Cherry Syrup)
• Packaging and Storage: Package in tight, light-resistant containers. Store at controlled room temperature, or in a cold place.
• Labeling: Label it to state that it is to be well shaken before use, and to state the Beyond-Use Date.
• Beyond-Use Date: NMT 60 days after the day on which it was compounded
• USP Reference Standards 11
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USP35NF30 Page 2063Pharmacopeial Forum: Volume No. 32(1) Page 44