Rezatomidine is also know as AGN-203818. AGN-203818 is a novel, potent and selective α2-adrenoreceptor antagonist under development for the treatment of chronic pain conditions, including neuropathic pain. AGN-203818 has been used in trials studying the treatment of Fibromyalgia, Cystitis, Interstitial, Irritable Bowel Syndrome, and Diabetic Neuropathy, Painful.

Physicochemical Properties

Molecular Formula	C13H16N2S
Molecular Weight	232.34454
Exact Mass	232.103
Elemental Analysis	C, 67.20; H, 6.94; N, 12.06; S, 13.80
CAS #	847829-38-3
PubChem CID	11287722
Appearance	Typically exists as solid at room temperature
LogP	3.467
Hydrogen Bond Donor Count	2
Hydrogen Bond Acceptor Count	1
Rotatable Bond Count	2
Heavy Atom Count	16
Complexity	311
Defined Atom Stereocenter Count	1
SMILES	CC1=C(C)C(=CC=C1)[C@H](C)C2=CN=C(N2)S
InChi Key	WQXVKEDUCPMRRI-JTQLQIEISA-N
InChi Code	InChI=1S/C13H16N2S/c1-8-5-4-6-11(9(8)2)10(3)12-7-14-13(16)15-12/h4-7,10H,1-3H3,(H2,14,15,16)/t10-/m0/s1
Chemical Name	4-[(1S)-1-(2,3-dimethylphenyl)ethyl]-1,3-dihydroimidazole-2-thione
Synonyms	Rezatomidine; 847829-38-3; UNII-W5LMZ0RC8I; AGN 203818 free base; AGN-203818; W5LMZ0RC8I; Rezatomidine [USAN:INN]; 2H-Imidazole-2-thione, 4-[(1S)-1-(2,3-dimethylphenyl)ethyl]-1,3-dihydro-;
HS Tariff Code	2934.99.9001
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)

Biological Activity

Targets	Alpha - adrenergic receptor.
ln Vivo	Developed for the treatment of chronic pain conditions. Phase II studies have evaluated its safety and effectiveness in treating pain in patients with fibromyalgia, irritable bowel syndrome, interstitial cystitis, and diabetic neuropathy.
Toxicity/Toxicokinetics	Pancreatitis, gastric ulcer, viral infections and dehydration were reported as serious adverse events in patients when administered a 60 - mg dose.
References	[1]. Current status of treatment and drug discovery for neuropathic pain. Acta Pharmaceutica Sinica, 2021, 56(3): 679-688.
Additional Infomation	Rezatomidine (AGN203818) is an alpha - adrenergic receptor agonist. However, three related phase II studies were terminated early based on a business decision.[1] Rezatomidine has been used in trials studying the treatment of Fibromyalgia, Cystitis, Interstitial, Irritable Bowel Syndrome, and Diabetic Neuropathy, Painful.

Solubility Data

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

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 : 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). 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 : PEG300：Tween 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). 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	4.3040 mL	21.5202 mL	43.0404 mL
	5 mM	0.8608 mL	4.3040 mL	8.6081 mL
	10 mM	0.4304 mL	2.1520 mL	4.3040 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.