M₃ muscarinic receptor (pKi = 7.78 at human recombinant m₃ receptor)
M₂ muscarinic receptor (pKi = 7.00 at human recombinant m₂ receptor) [1]
M₃ muscarinic receptor (used as a selective antagonist to confirm the role of M₃ receptors in choline-mediated vascular protection) [2]

Darifenacin antagonized the direct contractile responses to (+)-cis-dioxolane in rat isolated bladder strips with a pA₂ of 8.5 (unsurmountable antagonism).
In re-contractile responses induced under elevated adenyl cyclase activity following preferential alkylation of M₃ receptors, darifenacin antagonized the response with an apparent pK_B of 7.6 (intermediate between typical M₂ and M₃ affinities). [1]

In urethane-anesthetized rats, intravenous administration of darifenacin inhibited volume-induced bladder contractions with an ID₃₅%inh of 283.3 nmol kg⁻¹ and a maximal inhibition of 50.1%.
Pretreatment with propranolol did not significantly alter the inhibitory potency of darifenacin on volume-induced bladder contractions. [1]
In urethane-anesthetized rats subjected to superior mesenteric artery ischemia/reperfusion (I/R), pretreatment with darifenacin (0.1 mg·kg⁻¹, i.v.) 5 min before choline administration abolished the protective effects of choline on vascular function.
Specifically, darifenacin reversed the choline-induced attenuation of the enhanced contractile response to 5-HT and the impaired endothelium-dependent relaxation to ACh in mesenteric artery rings following I/R. [2]

Female Sprague-Dawley rats (200–300 g) were anesthetized with urethane. A bladder cannula was inserted via the urethra, and warm saline was infused to evoke volume-induced bladder contractions. Darifenacin was administered intravenously in cumulative doses at 10-minute intervals. In some experiments, propranolol (1 mg kg⁻¹, i.v.) was administered prior to darifenacin. [1]
Male adult Sprague-Dawley rats (8–10 weeks old) were anesthetized with pentobarbital sodium (40 mg·kg⁻¹, i.p.) and heparinized. The superior mesenteric artery was occluded for 60 min (ischemia) followed by 90 min of reperfusion. In the antagonist pretreatment group, darifenacin was administered intravenously at a dose of 0.1 mg·kg⁻¹, 5 min prior to choline (10 mg·kg⁻¹, i.v.) administration. Choline was given 10 min prior to the onset of ischemia. At the end of reperfusion, mesenteric arteries were isolated for ex vivo vascular reactivity studies. [2]

Absorption, Distribution and Excretion
The estimated average oral bioavailability at steady state is 15% for the 7.5 mg tablet and 19% for the 15 mg tablet. 163 L 40 L/h [Fast Metabolizer] 32 L/h [Slow Metabolizer] Metabolism/Metabolites Hepatic metabolism. Primarily mediated by cytochrome P450 enzymes CYP2D6 and CYP3A4. Half-life: The elimination half-life of finasteride after prolonged administration is approximately 13-19 hours. Biological Half-life The elimination half-life of finasteride after prolonged administration is approximately 13-19 hours.

Toxicity Summary
Dafinacin selectively antagonizes muscarinic M3 receptors. M3 receptors are involved in the contraction of smooth muscle in the human bladder and gastrointestinal tract, salivation, and the function of the iris sphincter. Hepatotoxicity
As with most anticholinergic drugs, dafinacin has not been associated with cases of significant liver injury, clinical symptoms, or jaundice, during treatment. In several prospective clinical trials of dafinacin in patients with overactive bladder, elevated ALT levels were reported in less than 1% of treatment subjects, similar to the placebo group. Although dafinacin has been widely used clinically for nearly two decades, there are no published case reports definitively indicating that clinically significant liver injury is caused by dafinacin. Probability Score: E (Unlikely to be the cause of clinically significant liver injury). Protein Binding Dafinacin binds to approximately 98% of plasma proteins (primarily α-1 acid glycoprotein).

[1]. Functional role of M2 and M3 muscarinic receptors in the urinary bladder of rats in vitro and in vivo. Br J Pharmacol, 1997, 120(8), 1409-1418.

[2]. Activation of M3 cholinoceptors attenuates vascular injury after ischaemia/reperfusion by inhibiting the Ca2+/calmodulin-dependent protein kinase II pathway. Br J Pharmacol. 2015 Dec;172(23):5619-33.

[3]. Evaluation of drug efflux transporter liabilities of darifenacin in cell culture models of the blood-brain and blood-ocular barriers. Neurourol Urodyn, 2011, 30(8), 1633-1638.

[4]. Acetylcholine acts through M3 muscarinic receptor to activate the EGFR signaling and promotes gastric cancer cell proliferation. Sci Rep. 2017 Jan 19;7:40802.

[5]. Effects of the M3 receptor selective muscarinic antagonist darifenacin on bladder afferent activity of the rat pelvic nerve. Eur Urol, 2007, 52(3), 842-847.

Darifenacin is 2-[(3S)-1-ethylpyrrolidone-3-yl]-2,2-diphenylacetamide, wherein a hydrogen atom at the 2-position of the ethyl group is replaced by a 2,3-dihydro-1-benzofuran-5-yl group. It is a selective antagonist of the M3 muscarinic acetylcholine receptor, which is primarily responsible for bladder muscle contraction. Darifenacin is used to treat urinary incontinence in the form of hydrobromide. It has the effects of a muscarinic receptor antagonist and an antispasmodic agent. It belongs to the 1-benzofuran, pyrrolidine, and monocarboxylic acid amide classes. Darifenacin (trade name: Enablex®, Novartis) is a drug used to treat urinary incontinence. Darifenacin blocks the M3 muscarinic acetylcholine receptor, which mediates bladder muscle contraction. This blocking effect reduces urinary urgency and therefore should not be used in patients with urinary retention. It is currently unclear whether M3 receptor selectivity has any clinical advantage in the treatment of overactive bladder.
Dapfenac is a muscarinic acetylcholine receptor antagonist. Its mechanism of action is as a muscarinic acetylcholine receptor antagonist.
Dapfenac is an anticholinergic and antispasmodic drug used to treat urinary incontinence and overactive bladder. Dafinac has not been shown to cause elevated liver enzymes or clinically significant acute liver injury.
Dapfenac (trade name: Enablex®, Novartis) is a medication used to treat urinary incontinence.
Dapfenac works by blocking M3 muscarinic acetylcholine receptors, which are primarily responsible for bladder muscle contraction. Therefore, it can relieve urinary urgency symptoms. It should not be used in patients with urinary retention.
It is currently unclear whether this selectivity for M3 receptors translates into a clinical advantage in treating symptoms of overactive bladder.
See also: Dafinac hydrobromide (salt form). Drug Indications Dafinacin is indicated for the treatment of overactive bladder with symptoms of urge incontinence, urgency, and frequency. FDA Label Mechanism of Action Dafinacin selectively antagonizes the muscarinic M3 receptor. The M3 receptor is involved in the contraction of smooth muscle in the human bladder and gastrointestinal tract, salivation, and iris sphincter function. Pharmacodynamics Dafinacin is a competitive muscarinic receptor antagonist. In vitro studies have shown that dafinacin has a higher affinity for the M3 receptor than other known muscarinic receptors (9-fold and 12-fold higher affinity for the M3 receptor compared to M1 and M5, respectively; and 59-fold higher affinity for the M3 receptor compared to M2 and M4). Muscarinic receptors play important roles in a variety of important cholinergic-mediated functions, including bladder smooth muscle contraction and salivation stimulation. Adverse drug reactions, such as dry mouth, constipation, and visual disturbances, may be mediated by affecting M3 receptors in these organs. Dalipenacin is a muscarinic receptor antagonist selective for the M₃ subtype. In rat bladders, M₃ receptors mediate direct contraction, while M₂ receptors may indirectly promote contraction by reversing β-adrenergic receptor-mediated relaxation. Dalipenacin has been used as a pharmacological tool to differentiate M₃ receptor-mediated responses. [1] This study used dalipenacin as a selective M₃ muscarinic receptor antagonist to pharmacologically demonstrate that the vasoprotective effect of choline on ischemia/reperfusion injury is mediated by specific activation of M₃ receptors. The effect of dalipenacin is consistent with that of another M₃ receptor antagonist, 4-DAMP. [2]

C28H30N2O2

426.55

426.23

133099-04-4

(±)-Darifenacin;133033-93-9;Darifenacin hydrobromide;133099-07-7;Darifenacin-d4;1095598-84-7

444031

White to off-white solid powder

1.2±0.1 g/cm3

614.3±55.0 °C at 760 mmHg

325.3±31.5 °C

0.0±1.8 mmHg at 25°C

1.624

4.5

1

3

7

32

607

1

C1CN(C[C@@H]1C(C2=CC=CC=C2)(C3=CC=CC=C3)C(=O)N)CCC4=CC5=C(C=C4)OCC5

HXGBXQDTNZMWGS-RUZDIDTESA-N

InChI=1S/C28H30N2O2/c29-27(31)28(23-7-3-1-4-8-23,24-9-5-2-6-10-24)25-14-17-30(20-25)16-13-21-11-12-26-22(19-21)15-18-32-26/h1-12,19,25H,13-18,20H2,(H2,29,31)/t25-/m1/s1

2-[(3S)-1-[2-(2,3-dihydro-1-benzofuran-5-yl)ethyl]pyrrolidin-3-yl]-2,2-diphenylacetamide

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)

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

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.

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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).

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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 : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)

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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

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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.

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