Chemical Identity and Physicochemical Properties

Acetazolamide sodium (SKU: A655464; MCE reference HY-B0782A) is the sodium salt of acetazolamide, a sulfonamide-derived carbonic anhydrase (CA) inhibitor. Converting acetazolamide to its sodium salt markedly improves aqueous solubility compared with the parent free acid, which has limited water solubility. This property makes the sodium salt form particularly suitable for preparing aqueous stock solutions and for intravenous or intraperitoneal administration in animal studies.

The compound acts by inhibiting the zinc-containing metalloenzyme carbonic anhydrase, which catalyses the reversible reaction: CO₂ + H₂O ⇌ HCO₃⁻ + H⁺. Inhibition of CA isoforms (notably CA II, CA IV, and CA XII) underpins the compound's diverse pharmacological effects studied in research settings, including reduced aqueous humor secretion, systemic metabolic acidosis, and diuresis.

Stock Solution Preparation and Solubility Guidelines

Recommended solvent: Acetazolamide sodium is most readily dissolved in ultrapure water (Milli-Q or equivalent) or phosphate-buffered saline (PBS, pH 7.4) to prepare stock solutions. The sodium salt form dissolves more readily in aqueous buffers than the free acid form of acetazolamide.

Preparation steps:

1. Allow the vial to equilibrate to room temperature before opening to minimise condensation.
2. Calculate the required mass for your target concentration (e.g., 10 mM or 50 mM stock).
3. Add the appropriate volume of sterile ultrapure water or PBS to the vial, and vortex gently until fully dissolved.
4. For concentrations that are slow to dissolve, warm briefly to 37 °C in a water bath and vortex again. Avoid prolonged heating.
5. Filter-sterilise through a 0.22 µm membrane filter if the solution will be used in cell culture.

Note: Working concentrations should be optimised empirically for each experimental system. Verify solubility at your target concentration before committing to large-scale experiments.

Storage Conditions and Stability

Recommended storage: Store Acetazolamide sodium (A655464) as a dry powder at −20 °C, protected from light and moisture. Under these conditions the solid compound is expected to be stable for at least 2 years from the date of manufacture when stored properly; however, researchers should verify stability with the certificate of analysis (CoA) supplied with each lot.

Solution stability: Prepared stock solutions should be aliquoted into single-use volumes to avoid repeated freeze–thaw cycles, which can degrade the compound over time. Store aliquots at −20 °C and use within a validated period. Once thawed, do not refreeze; use within 24–48 hours when held at 4 °C or within the working session if held at room temperature.

Handling precautions: Work in a well-ventilated area or under a fume hood when handling dry powder. Wear appropriate personal protective equipment (PPE) including gloves, lab coat, and eye protection. Acetazolamide sodium is a sulfonamide; individuals with known sulfonamide sensitivity should exercise caution and consult institutional safety guidelines.

Experimental Applications and Dosing Guidance

Acetazolamide sodium is used across a range of research models. Below are common application contexts; researchers should consult primary literature and optimise conditions for their specific experimental systems:

• In vitro carbonic anhydrase inhibition assays: Acetazolamide sodium is a reference standard inhibitor used to characterise CA isoform selectivity of novel compounds. Typical inhibitory concentrations (IC₅₀ values) for acetazolamide against CA II are in the low nanomolar range; specific values should be confirmed from validated literature or the supplier's datasheet.
• Cell-based studies: Used to probe effects of CA inhibition on intracellular pH regulation, cell proliferation, and hypoxia-inducible factor (HIF) pathways. Concentrations typically range from low micromolar to hundreds of micromolar depending on the cell line and endpoint measured.
• In vivo models: Administered via intraperitoneal (i.p.) or intravenous (i.v.) routes in rodent models of glaucoma, altitude sickness, epilepsy, and metabolic acidosis. Dose selection should be guided by published protocols and institutional IACUC/ethics approvals.
• Aqueous humor and intraocular pressure (IOP) studies: Frequently used as a positive control in IOP-lowering studies due to its well-established mechanism of reducing aqueous humor formation.

Important: All working concentrations, dosing regimens, and administration routes must be empirically validated and should not be extrapolated directly from this guideline without reference to relevant primary literature.

Quality, Purity, and Regulatory Considerations

Certificate of Analysis (CoA): Each lot of Acetazolamide sodium (A655464) is accompanied by a CoA specifying purity, appearance, and analytical data. Researchers should download the lot-specific CoA from the Aladdin Scientific website using the lot number printed on the product label before commencing experiments.

Purity verification: For sensitive assays, independent purity verification by HPLC or NMR may be warranted, particularly for GLP or regulatory-adjacent studies. If purity specifications are critical to your study, contact Aladdin Scientific technical support to obtain detailed analytical data.

Research use only: Acetazolamide sodium supplied by Aladdin Scientific (A655464) is intended for in vitro and in vivo research purposes only. It is not approved for, and must not be used in, clinical, diagnostic, therapeutic, food, drug, device, or cosmetic applications without appropriate regulatory authorisation.

Lot-to-lot consistency: When comparing results across experiments performed at different times, note the lot numbers used and check for any specification changes that may affect biological activity.