Clemizole

Alias: Clemizole; AL 20; AL20; AL-20; P 48; Reactrol
Cat No.:V3412 Purity: ≥98%
Clemizole (also known as AL 20, P 48, and/or Reactrol), is a potent inhibitor of transient receptor potential channel TRPC5 (Canonical transient receptor potential channel 5) and also an H1 histamine receptor antagonist.
Clemizole Chemical Structure CAS No.: 442-52-4
Product category: Histamine Receptor
This product is for research use only, not for human use. We do not sell to patients.
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Other Forms of Clemizole:

  • Clemizole hydrochloride
Official Supplier of:
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Purity & Quality Control Documentation

Purity: ≥98%

Product Description

Clemizole (also known as AL 20, P 48, and/or Reactrol), is a potent inhibitor of transient receptor potential channel TRPC5 (Canonical transient receptor potential channel 5) and also an H1 histamine receptor antagonist. It is discovered to significantly impede HCV replication. Clemizole's EC50 for viral replication is 8 µM, while its IC50 for RNA binding by NS4B is 24±1 nM. With an IC50 of 1.0-1.3 µM, clemizole effectively inhibits both Ca(2+) entry and TRPC5 currents in the low micromolar range. Not only did clemizole effectively block native TRPC5-like currents in the U-87 glioblastoma cell line, but it also effectively blocked heterologously expressed TRPC5 homomers and TRPC1:TRPC5 heteromers.

Biological Activity I Assay Protocols (From Reference)
Targets
NS4B ( IC50 = 24 nM ); H1 histamine receptor
ln Vitro

In vitro activity: Clemizole hydrochloride is discovered to have minimal toxicity for the host cell and to suppress NS4B's RNA binding, which inhibits HCV RNA replication in cell culture. Approximately 18 µM, or 2.25 times the EC50 of the wild-type RNA, is the Clemizole EC50 on the W55R mutant J6/JFH RNA[1]. A new inhibitor of TRPC5 channels is clemizole. In the low micromolar range (IC50=1.0-1.3 µM), clemizole effectively inhibits TRPC5 currents and Ca2+ entry. Clemizole shows a nearly 10-fold selectivity over TRPC3 (IC50=9.1 µM) and TRPC6 (IC50=11.3 µM), and a six-fold selectivity for TRPC5 over TRPC4β (IC50=6.4 µM), the closest structural relative of TRPC5. A new inhibitor of TRPC5, clemizole hydrochloride, has a half-maximal inhibitory concentration of 1.1 µM. A concentration-dependent block of TRPC5 by Clemizole was confirmed by the concentration-response curves, which also showed an apparent IC50 of 1.1±0.04 µM[2].

ln Vivo
Clemizole hydrochloride has an incredibly short plasma half-life (measured at 0.15 hours); in C57BL/6J mice, it biotransforms very quickly into a variety of lesser metabolites as well as a glucuronide (M14) and a dealkylated metabolite (M12)[3].
Enzyme Assay
Clemizole has an IC50 of 24±1 nM for RNA binding by NS4B and an EC50 of 8 µM for viral replication. In the low micromolar range (IC50 = 1.0-1.3 µM), clemizole effectively inhibits TRPC5 currents and Ca(2+) entry.
Cell Assay
Huh7.5 cells are kept in DMEM with 10% FBS, 1% L-glutamine, 1% Penicillin, 1% Streptomycin, and 1% non-essential amino acids added. Following treatment with 0.05% trypsin-0.02% EDTA and seeding at a 1:5 dilution, cell lines are passaged twice a week. Trypsinization and centrifugation at 700 g for five minutes are used to gather subconfluent Huh7.5 cells. After three ice-cold RNase-free PBS washes, the cells are resuspended in PBS at a density of 1.5 x 107 cells/mL. Using the T7 MEGAscript kit, XbaI linearized DNA templates are transcriptionally generated to create wild-type or mutant FL-J6/JFH-5′C19Rluc2AUbi RNA for electroporation. This is followed by purification (RNA transcription and fluorescent labeling). In a 2-mm-gap cuvette (BTX), we combined 5 µg of RNA with 400 µL of washed Huh7.5 cells. We then pulsed (0.82 kV, five 99 µs pulses) using a BTX-830 electroporator. Pulsed cells are diluted into 10 mL of growth medium that has been preheated after a 10-minute recovery period at 25°C. Six-well plates are seeded with a common stock of cells from multiple electroporations (5×105 cells per well). Following a 24-hour period, the medium is changed, and the cells are cultured with successive dilutions of the different inhibitory substances (such as Clemizole hydrochloride) found in the screen. Analysis is done on 17 of the 18 identified compounds that are commercially available. Regarding water-soluble compounds, untreated cells are employed as a negative control. Cells that have not been treated are cultured in the presence of equivalent concentrations of the solvent as a negative control for compounds (like Clemizole hydrochloride) that have been solubilized in DMSO. The medium is swapped out every day. Both a luciferase assay and a viability assay based on Alamar Blue are performed on the cells 72 hours after treatment. Cells are incubated for three hours at 37°C with 10% Alamar Blue reagent following a 72-hour treatment period. The FLEXstation II 384 is then used to scan the plates and detect fluorescence. The normalization of the signal with respect to untreated samples or samples grown in the presence of DMSO depends on the solvent used to dissolve the inhibitory compound (e.g., Clemizole hydrochloride), water, or DMSO[1].
Animal Protocol
Mice: Blood samples are taken 30 minutes after the oral administration of Clemizole at a dose of 25 mg/kg to eight control NOG mice and eight humanized TK-NOG mice. Blood samples are taken for analysis at 15, 30, and 1, 2, 4, and 6 hours after the oral clemizole (25 mg/kg) is administered to three C57BL/6J mice per time point. Eight humanized TK-NOG mice are administered Clemizole (25 mg/kg by mouth) with or without Ritonavir (20 mg/kg by mouth) for the DDI studies. Thirty minutes after administration, blood samples are taken. Additionally, six of these mice receive oral Debrisoquine (10 mg/kg) either with or without Ritonavir (20 mg/kg), and two hours later, plasma samples are taken for examination.
References

[1]. Discovery of a hepatitis C target and its pharmacological inhibitors by microfluidic affinity analysis. Nat Biotechnol. 2008 Sep;26(9):1019-27.

[2]. Clemizole hydrochloride is a novel and potent inhibitor of transient receptor potential channel TRPC5. Mol Pharmacol. 2014 Nov;86(5):514-21.

[3]. Using chimeric mice with humanized livers to predict human drug metabolism and a drug-drug interaction. J Pharmacol Exp Ther. 2013 Feb;344(2):388-96.

These protocols are for reference only. InvivoChem does not independently validate these methods.
Physicochemical Properties
Molecular Formula
C19H20CLN3
Molecular Weight
325.8352
Exact Mass
325.13
Elemental Analysis
C, 70.04; H, 6.19; Cl, 10.88; N, 12.90
CAS #
442-52-4
Related CAS #
Clemizole hydrochloride; 1163-36-6; Clemizole-d4; 6011-39-8 (penicillin); 17162-20-8 (sulfate)
Appearance
Solid powder
SMILES
C1CCN(C1)CC2=NC3=CC=CC=C3N2CC4=CC=C(C=C4)Cl
InChi Key
CJXAEXPPLWQRFR-UHFFFAOYSA-N
InChi Code
InChI=1S/C19H20ClN3/c20-16-9-7-15(8-10-16)13-23-18-6-2-1-5-17(18)21-19(23)14-22-11-3-4-12-22/h1-2,5-10H,3-4,11-14H2
Chemical Name
1-[(4-chlorophenyl)methyl]-2-(pyrrolidin-1-ylmethyl)benzimidazole
Synonyms
Clemizole; AL 20; AL20; AL-20; P 48; Reactrol
HS Tariff Code
2934.99.03.00
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)
Solubility Data
Solubility (In Vitro)
DMSO: ~65 mg/mL (~199.5 mM)
Water:<1 mg/mL
Ethanol:
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
(e.g. IP/IV/IM/SC)
Injection Formulation 1: DMSO : Tween 80: Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution 50 μL Tween 80 850 μL Saline)
*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 : PEG300Tween 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).
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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)]
*Preparation of 20% SBE-β-CD in Saline (4°C,1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.
Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin 500 μL Saline)
Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO 100 μLPEG300 200 μL castor oil 650 μL Saline)
Injection Formulation 7: Ethanol : Cremophor : Saline = 10: 10 : 80 (i.e. 100 μL Ethanol 100 μL Cremophor 800 μL Saline)
Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline
Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH 900 μL Corn oil)
Injection Formulation 10: EtOH : PEG300Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH 400 μLPEG300 50 μL Tween 80 450 μL 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).
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Oral Formulation 3: Dissolved in PEG400
Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose
Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose
Oral Formulation 6: Mixing with food powders


Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.

 (Please use freshly prepared in vivo formulations for optimal results.)
Preparing Stock Solutions 1 mg 5 mg 10 mg
1 mM 3.0690 mL 15.3450 mL 30.6899 mL
5 mM 0.6138 mL 3.0690 mL 6.1380 mL
10 mM 0.3069 mL 1.5345 mL 3.0690 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.

Calculator

Molarity Calculator allows you to calculate the mass, volume, and/or concentration required for a solution, as detailed below:

  • Calculate the Mass of a compound required to prepare a solution of known volume and concentration
  • Calculate the Volume of solution required to dissolve a compound of known mass to a desired concentration
  • Calculate the Concentration of a solution resulting from a known mass of compound in a specific volume
An example of molarity calculation using the molarity calculator is shown below:
What is the mass of compound required to make a 10 mM stock solution in 5 ml of DMSO given that the molecular weight of the compound is 350.26 g/mol?
  • Enter 350.26 in the Molecular Weight (MW) box
  • Enter 10 in the Concentration box and choose the correct unit (mM)
  • Enter 5 in the Volume box and choose the correct unit (mL)
  • Click the “Calculate” button
  • The answer of 17.513 mg appears in the Mass box. In a similar way, you may calculate the volume and concentration.

Dilution Calculator allows you to calculate how to dilute a stock solution of known concentrations. For example, you may Enter C1, C2 & V2 to calculate V1, as detailed below:

What volume of a given 10 mM stock solution is required to make 25 ml of a 25 μM solution?
Using the equation C1V1 = C2V2, where C1=10 mM, C2=25 μM, V2=25 ml and V1 is the unknown:
  • Enter 10 into the Concentration (Start) box and choose the correct unit (mM)
  • Enter 25 into the Concentration (End) box and select the correct unit (mM)
  • Enter 25 into the Volume (End) box and choose the correct unit (mL)
  • Click the “Calculate” button
  • The answer of 62.5 μL (0.1 ml) appears in the Volume (Start) box
g/mol

Molecular Weight Calculator allows you to calculate the molar mass and elemental composition of a compound, as detailed below:

Note: Chemical formula is case sensitive: C12H18N3O4  c12h18n3o4
Instructions to calculate molar mass (molecular weight) of a chemical compound:
  • To calculate molar mass of a chemical compound, please enter the chemical/molecular formula and click the “Calculate’ button.
Definitions of molecular mass, molecular weight, molar mass and molar weight:
  • Molecular mass (or molecular weight) is the mass of one molecule of a substance and is expressed in the unified atomic mass units (u). (1 u is equal to 1/12 the mass of one atom of carbon-12)
  • Molar mass (molar weight) is the mass of one mole of a substance and is expressed in g/mol.
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Reconstitution Calculator allows you to calculate the volume of solvent required to reconstitute your vial.

  • Enter the mass of the reagent and the desired reconstitution concentration as well as the correct units
  • Click the “Calculate” button
  • The answer appears in the Volume (to add to vial) box
In vivo Formulation Calculator (Clear solution)
Step 1: Enter information below (Recommended: An additional animal to make allowance for loss during the experiment)
Step 2: Enter in vivo formulation (This is only a calculator, not the exact formulation for a specific product. Please contact us first if there is no in vivo formulation in the solubility section.)
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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.

Clinical Trial Information
NCT Number Recruitment interventions Conditions Sponsor/Collaborators Start Date Phases
NCT00945880 Completed Drug: clemizole hydrochloride Hepatitis C Eiger BioPharmaceuticals July 2009 Phase 1
NCT04462770 Completed Drug: Placebo
Drug: EPX-100
(Clemizole HCl)
Dravet Syndrome Epygenix September 15, 2020 Phase 2
NCT04069689 Completed Drug: Placebos
Drug: EPX-100
(Clemizole Hydrochloride)
Dravet Syndrome Epygenix August 29, 2019 Phase 1
Biological Data
  • Clemizole


    Electrophysiological characterization of clemizole-mediated TRPC5 block.2014 Nov;86(5):514-21

  • Clemizole


    Clemizole-mediated block of TRPC5 is independent from intracellular components.2014 Nov;86(5):514-21

  • Clemizole


    Concentration-dependent inhibition of TRPC5 by clemizole.2014 Nov;86(5):514-21

  • Clemizole


    Clemizole-mediated effect on other TRP channels.2014 Nov;86(5):514-21

  • Clemizole


    Clemizole blocks riluzole-activated heteromeric TRPC1:TRPC5 and endogenously expressed TRPC5 channels in U87 glioblastoma cells.2014 Nov;86(5):514-21

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