Name: Phentolamine Mesylate
Brand: Selleck Chemicals
SKU: S2038
Availability: InStock
Rating: 5 (5 reviews)

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Quality Control

Batch: Purity: 99.96%

99.96

Related Targets	AChR 5-HT Receptor COX Calcium Channel Histamine Receptor Dopamine Receptor GABA Receptor TRP Channel Cholinesterase (ChE) GluR
Other Adrenergic Receptor Inhibitors	ICI 118551 Hydrochloride (Zenidolol) L755507 Yohimbine HCl Atipamezole Higenamine hydrochloride Noradrenaline bitartrate monohydrate Fenoterol hydrobromide Medetomidine HCl Isoprenaline L-Adrenaline

Solubility

In vitro
Batch:

DMSO : 76 mg/mL (201.34 mM)
(Moisture-contaminated DMSO may reduce solubility. Use fresh, anhydrous DMSO.)

Water : 76 mg/mL

Ethanol : 76 mg/mL

Molarity Calculator

Mass	Concentration	Volume	Molecular Weight
Mass value Mass unit	Concentration value Concentration unit	Volume value Volume unit	Molecular weight (g/mol)

Dilution Calculator Molecular Weight Calculator

In vivo batch selection In vivo Batch:
Homogeneous suspension	CMC-NA	≥5mg/ml	Taking the 1 mL working solution as an example, add 5 mg of this product to 1 ml of CMC-Na solution, mix evenly to obtain a homogeneous suspension with a final concentration of 5 mg/ml.
Homogeneous suspension	CMC-NA	≥5mg/ml	Taking the 1 mL working solution as an example, add 5 mg of this product to 1 ml of CMC-Na solution, mix evenly to obtain a homogeneous suspension with a final concentration of 5 mg/ml.
Homogeneous suspension	CMC-NA	≥5mg/ml	Taking the 1 mL working solution as an example, add 5 mg of this product to 1 ml of CMC-Na solution, mix evenly to obtain a homogeneous suspension with a final concentration of 5 mg/ml.

In vivo Formulation Calculator (Clear solution)

Step 1: Enter information below (Recommended: An additional animal making an allowance for loss during the experiment)

Dosage: mg/kg

Average weight of animals: g

Dosing volume per animal: μL

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Step 2: Enter the in vivo formulation (This is only the calculator, not formulation. Please contact us first if there is no in vivo formulation at the solubility Section.)

% DMSO

%

% Tween 80

% ddH₂O

% DMSO

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Calculation results:

Working concentration: mg/ml;

Method for preparing DMSO master liquid: mg drug pre-dissolved in μL DMSO ( Master liquid 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 master liquid, next addμL PEG300, mix and clarify, next addμL Tween 80, mix and clarify, next add μL ddH₂O, mix and clarify.

Method for preparing in vivo formulation: Take μL DMSO master liquid, next add μL Corn oil, mix and clarify.

Note: 1. Please make sure the liquid is clear before adding the next solvent.
2. Be sure to add the solvent(s) in order. You must ensure that the solution obtained, in the previous addition, is a clear solution before proceeding to add the next solvent. Physical methods such
as vortex, ultrasound or hot water bath can be used to aid dissolving.

Chemical Information, Storage & Stability

Molecular Weight	377.46	Formula	C₁₇H₁₉N₃O.CH₄O₃S	Storage (From the date of receipt)	3 years-20°Cpowder
CAS No.	65-28-1	Download SDF		Storage of Stock Solutions	1 year-80°Cin solvent 1 month-20°Cin solvent
Synonyms	Phentolamine methanesulfonate			SMILES	CC1=CC=C(C=C1)N(CC2=NCCN2)C3=CC(=CC=C3)O.CS(=O)(=O)O

Read more about storage stability stock solution CAS number SMILES

Mechanism of Action

Targets/IC₅₀/Ki	α-adrenergic receptor
In vitro	Phentolamine mesylate displaces binding of the selective alpha 1 receptor antagonists [¹²⁵I]HEAT and [³H]prazosin and the alpha 2 receptor antagonists [³H]rauwolscine and [³H]RX 821002 with relatively high affinity in corpus cavernosum membranes. Phentolamine mesylate causes concentration dependent relaxation in erectile tissue strips pre-contracted with adrenergic agonists phenylephrine, norepinephrine, oxymetazoline and UK 14,304, as well as with non-adrenergic contractile agents Endothelin and KCl. Phentolamine mesylate induces relaxation of corpus cavernosum erectile tissue by direct antagonism of alpha 1 and 2 adrenergic receptors and by indirect functional antagonism via a non-adrenergic, endothelium-mediated mechanism suggesting nitric oxide synthase activation. Phentolamine, an alpha-adrenergic antagonist, blocks the vasoconstriction associated with the epinephrine used in dental anesthetic formulations, thus enhancing the systemic absorption of the local anesthetic from the injection site.
In vivo	Phentolamine is a reversible competitive alpha-adrenergic antagonist with similar affinities for alphal and alpha2 receptors. Phentolamine mesylate causes vasodilatation and thus hypotension by decreasing peripheral vascular resistance. Phentolamine mesylate (30 and 100 nM) dose-dependently enhances electrical field stimulation-induced relaxation of the rabbit corpus cavernosum. Phentolamine relaxes rabbit corpus cavernosum independent of alpha-adrenergic receptor blockade. Phentolamine mesylate relaxes nonadrenergic noncholinergic neurons of the rabbit corpus cavernosum by activating NO synthase and is independent of alpha-adrenergic receptor blockade.
References	[1] https://pubmed.ncbi.nlm.nih.gov/9884917/ [2] https://pubmed.ncbi.nlm.nih.gov/18547152/ [3] https://pubmed.ncbi.nlm.nih.gov/8583353/ [4] https://pubmed.ncbi.nlm.nih.gov/11468007/

Clinical Trial Information

(data from https://clinicaltrials.gov, updated on 2026-07-24)

NCT Number	Recruitment	Conditions	Sponsor/Collaborators	Start Date	Phases
NCT07726433	RECRUITING	Chemotherapy-Induced Nausea and Vomiting (CINV)	Tianjin Medical University Cancer Institute and Hospital	2026-06-15	PHASE2
NCT05997732	RECRUITING	Vasoconstriction; Vasodilation	University of Alberta	2023-10-31	PHASE4
NCT05219799	RECRUITING	Obesity; Vasodilation; Healthy	University of Missouri-Columbia	2023-03-14	EARLY_PHASE1
NCT06787066	RECRUITING	Menopause	University of Missouri-Columbia	2025-07-10	EARLY_PHASE1
NCT03318094	ACTIVE_NOT_RECRUITING	Insulin Resistance; Healthy; Obesity	Vanderbilt University Medical Center	2017-10-24	PHASE1
NCT02966665	RECRUITING	Chronic Obstructive Pulmonary Disease; Pulmonary Artery Hypertension; Heart Failure; Hypertension	Russell Richardson	2008-09	PHASE1

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Phentolamine Mesylate Adrenergic Receptor antagonist

Chemical Structure

Molecular Weight: 377.46