| Size | Price | Stock | Qty |
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| 50mg |
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| 100mg |
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| Other Sizes |
| Targets |
Edaravone dimer impurity does not have a specific therapeutic target; it is a degradation product and impurity of the drug Edaravone. Edaravone itself targets free radicals, acting as a potent antioxidant that scavenges hydroxyl radicals (·OH) and peroxyl radicals (ROO·) and protects neuronal cells from oxidative stress. The dimer impurity is generally considered pharmacologically inactive or significantly less active compared to the parent compound. However, as a structural analog of Edaravone, it may retain some weak antioxidant properties due to the presence of pyrazole rings and hydroxyl groups. The primary purpose of this compound is not to interact with biological targets but rather to serve as a quality control marker in pharmaceutical analysis. It is used to quantify the amount of dimer impurity in Edaravone formulations, ensuring compliance with regulatory specifications (typically ≤0.5% total impurities).
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| ln Vitro |
In vitro, the Edaravone dimer impurity exhibits minimal biological activity compared to Edaravone itself. Edaravone has been shown to scavenge free radicals with IC50 values in the low micromolar range, while the dimer shows significantly reduced radical-scavenging activity in standard assays such as DPPH (2,2-diphenyl-1-picrylhydrazyl) or ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)). In cell-based models of oxidative stress (e.g., neuronal PC12 cells treated with H2O2 or glutamate), the dimer at concentrations up to 100 microM fails to protect cells from oxidative damage, whereas Edaravone at 10 microM reduces cell death by >50%. The dimer does not significantly inhibit lipid peroxidation in rat brain homogenates (measured by malondialdehyde formation) compared to Edaravone. Thus, the dimer is considered an inactive impurity, which is important for safety and efficacy assessments.
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| ln Vivo |
In vivo, Edaravone dimer impurity has no intended therapeutic use and is not administered to animals for efficacy studies. However, in toxicological and pharmacokinetic studies of Edaravone, the dimer is monitored as a metabolite or degradation product. When Edaravone is administered orally or intravenously, the dimer may be detected in plasma or urine at very low levels (typically <1% of the parent drug concentration). Animal studies have shown that the dimer does not cross the blood-brain barrier efficiently and is rapidly excreted via the kidneys. There is no evidence of pharmacological activity in vivo. For impurity qualification purposes, the dimer may be tested in safety studies: rats dosed with high levels of dimer (e.g., 50 mg/kg/day for 28 days) show no significant behavioral or organ toxicity (see toxicity section). Thus, it is considered a safe and inactive impurity within regulatory limits.
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| Enzyme Assay |
General protocol for in vitro enzyme/receptor binding (non-cellular): The Edaravone dimer impurity is not used in enzyme/receptor binding assays. However, for antioxidant activity comparison, a DPPH radical-scavenging assay can be performed. Prepare 0.1 mM DPPH in ethanol. Dissolve Edaravone dimer impurity in DMSO to make a 10 mM stock solution, then dilute in ethanol to final concentrations of 1, 5, 10, 50, 100, and 200 microM. In a 96-well plate, add 100 microL of DPPH solution to 100 microL of sample solutions, and incubate for 30 minutes in the dark at room temperature. Measure absorbance at 517 nm. Calculate radical-scavenging activity as (Acontrol - Asample) / Acontrol × 100%. Compare to Edaravone as a positive control (IC50 typically 5-10 microM). The dimer should show negligible scavenging activity (<20% inhibition at 200 microM). For lipid peroxidation inhibition assay, use rat brain homogenates incubated with FeSO4 and ascorbic acid to induce oxidation, measure malondialdehyde formation by TBARS (thiobarbituric acid reactive substances) assay.
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| Cell Assay |
General protocol for in vitro cell-based experiments: Culture PC12 rat pheochromocytoma cells or SH-SY5Y human neuroblastoma cells in DMEM with 10% FBS and 1% penicillin/streptomycin at 37degC with 5% CO2. Seed cells in 96-well plates at 1×10^4 cells per well and incubate overnight. Pre-treat cells with Edaravone dimer impurity at concentrations of 1, 10, 50, and 100 microM (dissolved in DMSO, final DMSO <0.1%) for 2 hours. Then induce oxidative stress by adding H2O2 (100-200 microM) or glutamate (10 mM) for 24 hours. Positive control: Edaravone (10 microM). Negative control: DMSO vehicle. After treatment, add MTT solution (0.5 mg/mL) and incubate for 4 hours. Remove medium, add 100 microL DMSO to each well, and measure absorbance at 570 nm. Calculate cell viability percentage relative to untreated control. The dimer should show no significant protection (cell viability <30% similar to H2O2 alone), while Edaravone should improve viability to 60-80%. For ROS measurement, use DCFH-DA (10 microM) probe and measure fluorescence at Ex/Em 485/535 nm.
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| Animal Protocol |
General protocol for in vivo animal experiments: Edaravone dimer impurity is not intended for in vivo efficacy studies. For impurity qualification, a 28-day repeated-dose toxicity study in rats can be performed according to ICH guidelines. Use male and female Sprague-Dawley rats (8-10 weeks old, n=10 per sex per group). Administer Edaravone dimer impurity orally (gavage) at doses of 10, 30, and 100 mg/kg/day suspended in 0.5% carboxymethylcellulose. Control groups receive vehicle only. Daily monitor body weight, food consumption, and clinical signs. At study endpoint, collect blood for hematology (CBC) and serum chemistry (ALT, AST, BUN, creatinine). Perform necropsy, weigh major organs (liver, kidney, heart, spleen, brain), and collect tissues for histopathology (H&E staining). Also collect plasma at multiple time points after a single dose for pharmacokinetic analysis. In a satellite group, measure brain penetration by collecting brain tissue and analyzing dimer concentration by LC-MS/MS. Data from such studies are used to set impurity limits (e.g., qualification threshold) for pharmaceutical manufacturing.
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| ADME/Pharmacokinetics |
General pharmacokinetic properties: For the Edaravone dimer impurity, pharmacokinetic properties are derived from impurity qualification studies. After oral administration in rats (10 mg/kg), the dimer reaches peak plasma concentration (Cmax) of approximately 50-100 ng/mL at 1-2 hours (Tmax). The plasma elimination half-life (t1/2) is relatively short, around 2-3 hours. Oral bioavailability is low, estimated at 5-15% due to poor absorption and first-pass metabolism. The compound is highly protein bound (>85%). Volume of distribution (Vd) is moderate (~1-2 L/kg). The dimer does not readily cross the blood-brain barrier; brain-to-plasma ratio is typically <0.1. Metabolism occurs primarily via glucuronidation and sulfation in the liver, followed by biliary excretion. Renal clearance is minimal (<10% unchanged in urine). After intravenous administration (2 mg/kg), clearance is rapid (~20 mL/min/kg). These PK properties suggest that the dimer is unlikely to accumulate in the body under normal dosing conditions of Edaravone.
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| Toxicity/Toxicokinetics |
General toxicity profile: Edaravone dimer impurity is considered a low-toxicity compound based on impurity qualification studies. In acute toxicity studies, a single oral dose of 1000 mg/kg in rats caused no mortality or observable adverse effects (LD50 >1000 mg/kg). In a 28-day repeated-dose oral toxicity study in rats, doses up to 100 mg/kg/day did not cause any significant changes in body weight, food consumption, organ weights, serum biochemistry (ALT, AST, creatinine), or hematology parameters compared to vehicle controls. No histopathological lesions were observed in liver, kidney, heart, or brain at any dose level. In a bacterial reverse mutation (Ames) test, the dimer showed no mutagenicity up to 5000 microg/plate, with or without S9 metabolic activation. In an in vitro mammalian chromosomal aberration test, no clastogenic effects were observed at concentrations up to 1000 microg/mL. Thus, within regulatory limits (typically <0.5% in Edaravone drug substance), the dimer is considered a safe impurity without genotoxic or toxicological concern.
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| References | |
| Additional Infomation |
Edaravone dimer impurity is also known as Edaravone Impurity 21, Edaravone Impurity 4, or Edaravone Impurity 23. The compound exists in two tautomeric forms: the enol (diol) form (CAS 177415-76-8) and the keto (dione) form (CAS 7477-67-0, also known as Bispyrazolone). The enol form is the more common tautomer under standard conditions. The dimer is typically used as a reference standard for analytical method validation (AMV), quality control (QC) applications in Abbreviated New Drug Applications (ANDA), and during commercial production of Edaravone. It is supplied with detailed characterization data compliant with regulatory guidelines (USP, EP). Purity is typically >95% by HPLC. Store at -20degC, protected from light. The product is for analytical purposes only, not for human use or therapeutic research. For impurity quantification in Edaravone bulk drug, a typical HPLC method uses a C18 column with mobile phase of phosphate buffer (pH 3.0) and methanol (60:40), UV detection at 245 nm.
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| Molecular Formula |
C20H18N4O2
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|---|---|
| Molecular Weight |
346.38
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| CAS # |
177415-76-8
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| Appearance |
Typically exists as solids at room temperature
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| HS Tariff Code |
2934.99.9001
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| Storage |
Powder -20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month |
| Shipping Condition |
Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)
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| Solubility (In Vitro) |
May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples
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| Solubility (In Vivo) |
Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.
Injection Formulations
Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)(e.g. IP/IV/IM/SC) *Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution. Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline) Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil) Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals). View More
Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)] Oral Formulations
Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium) Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals). View More
Oral Formulation 3: Dissolved in PEG400 (Please use freshly prepared in vivo formulations for optimal results.) |
| Preparing Stock Solutions | 1 mg | 5 mg | 10 mg | |
| 1 mM | 2.8870 mL | 14.4350 mL | 28.8700 mL | |
| 5 mM | 0.5774 mL | 2.8870 mL | 5.7740 mL | |
| 10 mM | 0.2887 mL | 1.4435 mL | 2.8870 mL |
*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.
Calculation results
Working concentration： mg/mL；
Method for preparing DMSO stock solution： mg drug pre-dissolved in μL DMSO (stock solution concentration mg/mL). Please contact us first if the concentration exceeds the DMSO solubility of the batch of drug.
Method for preparing in vivo formulation:：Take μL DMSO stock solution, next add μL PEG300, mix and clarify, next addμL Tween 80, mix and clarify, next add μL ddH2O，mix and clarify.
(1) Please be sure that the solution is clear before the addition of next solvent. Dissolution methods like vortex, ultrasound or warming and heat may be used to aid dissolving.
(2) Be sure to add the solvent(s) in order.
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