D₂ Receptor ( Ki = 1.8 nM ); D₃ Receptor ( Ki = 3.5 nM ); D₄ Receptor ( Ki = 2400 nM ); D₁ Receptor ( Ki = 18000 nM )
Raclopride targets the D2 dopamine receptor as an antagonist. It also has affinity for the D3 receptor. By blocking these receptors, it inhibits dopamine-mediated signaling. This mechanism makes it useful for studying dopaminergic function and for PET imaging of dopamine receptors.

In vitro, Raclopride is a selective antagonist of dopamine D2/D3 receptor. Quantitative in vitro activity data, such as Ki values for D2 and D3 receptor binding, is not detailed in the publicly available sources.

Raclopride (0.1, 0.3, or 0.6 mg/kg; IP; 30 min; albino male mice; OF1 strain) dramatically shortens the amount of time that the mice spend engaging in aggressive behavior[2].

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Raclopride is a substituted benzamide with high selectivity as an antagonist of central dopaminergic D2 receptors and potential antipsychotic effects. In comparison with a classic DA receptor blocking agent like haloperidol, raclopride displays an atypical profile in preclinical tests for extrapyramidal side effects. Antiaggressive properties of raclopride on agonistic behavior have not yet been fully explored. In this work the effects of raclopride (0.1, 0.3, or 0.6 mg/kg) on aggressive and motor behaviors in male mice were studied. Aggression tests were performed 30 min after injections. Encounters were videotaped and behavior was evaluated, measuring the time spent in 11 broad categories of behavior. The results show a clear antiaggressive effect of raclopride, with very little motor impairment and some increase in exploratory behavior. This behavioral profile is very similar to the one observed with other atypical neuroleptics and differs somewhat from that found in the classic compounds.[2]
In vivo, 11C-radiolabelled raclopride is used in positron emission tomography (PET) scanning to assess the degree of dopamine binding to the D2 dopamine receptor. It is used as a PET radioligand for imaging dopamine D2 receptors in the brain. This application is valuable for studying neurological and psychiatric disorders involving dopaminergic dysfunction.

For cell-free assays, the binding affinity of Raclopride to D2 and D3 dopamine receptors can be measured using radioligand binding assays. Membrane preparations from cells expressing the receptors are incubated with a radiolabeled ligand specific for D2/D3 receptors (e.g., [3H]spiperone or [3H]raclopride) and varying concentrations of unlabeled Raclopride. Ki values are calculated from competition binding curves.

For in vitro cellular assays, the antagonistic activity of Raclopride at D2 and D3 receptors can be assessed in cells expressing these receptors. Cells are treated with Raclopride and stimulated with a dopamine agonist. The inhibition of agonist-induced responses, such as cAMP accumulation or calcium mobilization, is measured. The IC50 for receptor antagonism is calculated from dose-response curves.

Albino male mice of the OF1 strain
0.1, 0.3, or 0.6 mg/kg
i.p.
In vivo, Raclopride is used in PET imaging studies. The radiolabeled compound ([11C]raclopride) is administered intravenously to subjects (animals or humans). PET scans are performed to measure the binding of the radioligand to D2 receptors in the brain. The binding potential is calculated using kinetic modeling.

Raclopride (CAS 84225-95-6) has a molecular formula of C15H20Cl2N2O3 and a molecular weight of 347.24 g/mol. It is also known as FLA-870. Appearance: typically a powder. Solubility: DMSO and other organic solvents. Storage: typical for small-molecule compounds (desiccated, protected from light, -20°C). Purity: typically >98% for research use.

No detailed toxicity data is publicly available. As a D2 receptor antagonist, potential side effects may include extrapyramidal symptoms and other dopamine-related effects. At the doses used for PET imaging, the compound is generally well-tolerated.

[1]. Dopamine receptor pharmacology. Trends Pharmacol Sci. 1994 Jul;15(7):264-70.

[2]. Behavioral profile of raclopride in agonistic encounters between male mice. Pharmacol Biochem Behav. 1994;47(3):753-756.

3,5-Dichloro-N-[[(2S)-1-ethyl-2-pyrrolyl]methyl]-2-hydroxy-6-methoxybenzamide belongs to the salicylamide class of compounds. Raclapyribine has been used in research trials for Parkinson's disease. It is a substituted benzamide with antipsychotic properties. It is a dopamine D2 receptor (see “Receptor, Dopamine D2”) antagonist. Dopamine receptors are major targets for the treatment of schizophrenia, Parkinson's disease, and Huntington's disease, as discussed in this review by Philip Seeman and Hubert Van Tol. Drugs that selectively target specific subtypes of dopamine receptors can improve treatment efficacy. The degree to which most antipsychotic drugs block D2 receptors is directly related to clinical efficacy, except for clozapine, which tends to target D4 receptors. D1 and D2 receptors can mutually enhance each other, possibly through G protein subunits. In schizophrenia, the density of D2 and D3 receptors increases by 10%, while the density of D4 receptors increases by 600%. Therefore, the D4 receptor may become a target for future antipsychotic drugs. Although antipsychotic drugs initially helped in the discovery of dopamine receptors, the five currently cloned dopamine receptors are facilitating the discovery of selective antipsychotics and anti-Parkinson's disease drugs. Antipsychotics: These drugs can control manic psychotic behavior, alleviate acute psychotic states, reduce psychotic symptoms, and have a sedative effect. They are used to treat conditions such as schizophrenia, Alzheimer's disease, postoperative transient psychosis, or myocardial infarction. These drugs are often called neuroblockers, implying that they may produce neurological side effects, but not all antipsychotics produce such side effects. Many of these drugs may also be effective for nausea, vomiting, and itching. (See all compounds classified as antipsychotics.) Dopamine antagonists: These drugs bind to dopamine receptors but do not activate the receptors, thereby blocking the action of dopamine or exogenous agonists. Many medications used to treat psychotic disorders (antipsychotics) are dopamine antagonists, although their therapeutic effects may be attributed to long-term modulation of the brain rather than the acute effects of blocking dopamine receptors. Dopamine antagonists are also used in other clinical applications, including as antiemetics, for the treatment of Tourette syndrome, and for the treatment of hiccups. Dopamine receptor blocking is associated with neuroleptic malignancy.
Raclopride is a research-grade compound and is not approved for therapeutic use. It is primarily used as a pharmacological tool and as a PET radioligand for imaging dopamine D2 receptors. Its mechanism of action involves selective antagonism of D2 and D3 dopamine receptors. No clinical trials have been reported for therapeutic use.

C₁₅H₂₀CL₂N₂O₃

347.24

346.085

84225-95-6

Raclopride-d5 hydrochloride; 1217623-85-2; Raclopride tartrate; 98185-20-7

3033769

White to yellow solid powder

1.288g/cm3

420.3ºC at 760 mmHg

54 °C

208ºC

1.563

3.25

2

4

5

22

386

1

CCN1CCC[C@H]1CNC(=O)C2=C(C(=CC(=C2OC)Cl)Cl)O

WAOQONBSWFLFPE-VIFPVBQESA-N

InChI=1S/C15H20Cl2N2O3/c1-3-19-6-4-5-9(19)8-18-15(21)12-13(20)10(16)7-11(17)14(12)22-2/h7,9,20H,3-6,8H2,1-2H3,(H,18,21)/t9-/m0/s1

3,5-dichloro-N-[[(2S)-1-ethylpyrrolidin-2-yl]methyl]-2-hydroxy-6-methoxybenzamide

FLA 870; FLA-870; RACLOPRIDE; 84225-95-6; (S)-3,5-dichloro-N-((1-ethylpyrrolidin-2-yl)methyl)-2-hydroxy-6-methoxybenzamide; 3,5-dichloro-N-[[(2S)-1-ethylpyrrolidin-2-yl]methyl]-2-hydroxy-6-methoxybenzamide; CHEMBL8809; 430K3SOZ7G; DTXSID9045687; NCGC00025303-03; FLA870; Raclopride

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO: 69~100 mg/mL (198.7~288 mM)
Ethanol: ~69 mg/mL

Solubility in Formulation 1: ≥ 2.5 mg/mL (7.20 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (7.20 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
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.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (7.20 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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 (Please use freshly prepared in vivo formulations for optimal results.)