Orciprenaline sulfate

Chemical properties

White or almost white, slightly hygroscopic, crystalline powder.

Originator

Alupent, Boehringer Ingelheim ,W. Germany ,1961

The Uses of Orciprenaline sulfate

Beta2-adrenoceptor agonist; bronchodilator.

The Uses of Orciprenaline sulfate

Bronchodilatator;Beta-adrenergic agonist

What are the applications of Application

Metaproterenol hemisulfate salt is a β2-adrenoceptor agonist

Manufacturing Process

In an initial operation, 3,5-diacetoxyacetophenone was reacted first with bromine and then with isopropylamine to give 1-(3,5-dihydroxyphenyl)-2- isopropylaminoethanone.
59 g of 1-(3,5-dihydroxy-phenyl)-2-isopropylaminoethanone (free base) were dissolved in 590 cc of methanol, and the solution was hydrogenated in the presence of about 80 g Raney nickel at room temperature and under a pressure of 5 atm. Hydrogen absorption was terminated after a few minutes. The catalyst was separated by vacuum filtration, and the filtrate, an ethanolic solution of 1-(3,5-dihydroxyphenyl)-1-hydroxy-2-isopropylaminoethane, was admixed with the calculated amount of an alcoholic 20% sulfuric acid solution. A crystalline precipitate formed which was filtered off and washed with alcohol. For purification, the product was dissolved in water and the solution was filtered through iron-free charcoal.
Thereafter, the filtrate was evaporated to dryness in vacuo and the residue was taken up in alcohol. The crystalline precipitate which separated out after some standing was separated by vacuum filtration and washed with alcohol. After recrystallization from 90% alcohol, 61 g (83.2% of theory) of 1-(3,5- dihydroxyphenyl)-1-hydroxy-2-isopropylamino-ethane sulfate, MP 202° to 203°C, was obtained.

brand name

Alupent (Boehringer Ingelheim); Prometa (Muro).

Therapeutic Function

Bronchodilator

Pharmacokinetics

Metaproterenol is a direct-acting resorcinol analogue of isoproterenol. The N-isopropyl is β-directing, and the combination with the resorcinol ring system enhances the selectivity for the β2-receptors. It is the least potent of the β2-selective agonists, however, most likely because of the poor β2-selectivity of the isopropyl group. It has good oral bioavailability being resistant to COMT and only slowly metabolized by MAO. When administered orally, it has an onset of approximately 30 minutes with a 4-hour duration. Inhaled metaproterenol can have an onset as quick as 5 minutes; however, it can be as long as 30 minutes in susceptible individuals. Metaproterenol is available in tablet, syrup, and inhalation dosage forms and is recommended for bronchial asthma attacks and treatment of acute asthmatic attacks in children 6 years of age and older (5% solution for inhalation only). Metaproterenol has the same adverse effect profile as other adrenergic agonists, but with a decreased incidence of arrhythmias.