Labetalol hydrochloride

Chemical properties

White or almost white powder.

Chemical properties

Labetalol HCl is a white or off-white crystalline powder, soluble in water. Labetalol hydrochloride injection is a clear, colorless to light yellow, aqueous, sterile, isotonic solution for intravenous (IV) injection. It has a pH range of 3.0 to 4.5. Each mL contains 5 mg labetalol hydrochloride USP, 45 mg anhydrous dextrose, 0.10 mg edetate disodium; 0.80 mg of methylparaben and 0.10 mg of propylparaben as preservatives; and citric acid monohydrate and sodium hydroxide, as necessary, to bring the solution into the pH range^[1].

Originator

Trandate,Allen and Hanburys,UK,1977

The Uses of Labetalol hydrochloride

vasoconstrictor

The Uses of Labetalol hydrochloride

tropane alkaloid, anticholinergic drug

What are the applications of Application

Labetalol hydrochloride is a competitive α-AR (α-adrenoceptor) and β-AR (β-adrenoceptor) antagonist with antihypertensive properties

Definition

ChEBI: Labetalol hydrochloride is a member of salicylamides.

Indications

Labetalol hydrochloride is indicated for the control of blood pressure in patients with severe hypertension. Labetalol hydrochloride is also used to treat severe or mild pregnancy hypertension (PIH).

Manufacturing Process

(a) 5-Bromoacetylsalicylamide (2.6 g), N-benzyl-N-(1-methyl-3-phenylpropyl) amine (4.8 g) and methyl ethyl ketone (50 ml) were heated at reflux for 40 minutes. The solvent was removed and the residue was treated with benzene. The secondary amine hydrobromide was filtered off and discarded, and the filtrate was evaporated to dryness. The residue was treated with an excess of ethanolic hydrogen chloride when 5-[N-benzyl-N-(1-methyl-3-phenylpropyl)- glycyl]-salicylamide hydrochloride (1.15 g) crystallized out, MP 139°C to 141°C.
(b) 5-[N-benzyl-N-(1-methyl-3-phenylpropyl)glycyl]-salicylamide hydrochloride (0.75 g), 10% mixture of PdO and PtO on carbon catalyst (0.1 g) and ethanol (20 ml) were shaken at room temperature and pressure with hydrogen until uptake ceased. The catalyst was filtered off and the filtrate evaporated to dryness. The residue was crystallized from ethanol to give 5-[1- hydroxy-2-(1-methyl-3-phenylpropyl)aminoethyl]salicylamide hydrochloride as a white solid (0.40 g), MP 188°C.

brand name

Normodyne (Schering); Trandate (Promethus).

Therapeutic Function

Alpha-adrenergic blocker, Beta-adrenergic blocker

Biological Activity

labetalol hcl is a selective antagonist for the α1-adrenergic receptor and a non-selective antagonist for the β-adrenergic receptor. labetalol hcl has been used for the treatment of high blood pressure. labetalol hcl competitively targets the α1-adrenergic receptors expressed in vascular smooth muscle, thus inhibiting adrenergic stimulation on endothelial cells and vasoconstriction in peripheral blood vessels. labetalol hcl also blocks the β-adrenergic receptors in bronchial and vascular smooth muscle to counteract adrenergic stimulation. ultimately, labetalol hcl causes decreases in resting and exercise heart rates, cardiac output, as well as in both systolic and diastolic blood pressure, exherting vasodilation, as well as negative chronotropic and inotropic cardiac effects.1. national center for biotechnology information (2021). pubchem compound summary for cid 3869, labetalol. retrieved august 21, 2021.2. dage rc, hsieh cp. direct vasodilatation by labetalol in anaesthetized dogs. british journal of pharmacology, 1980, 70(2): 287-293.

References

[1] Labetalol Hydrochloride[J]. Definitions, 2020. DOI:10.1002/9780470909799.ch11.