Monoaminopropyl analogues

SYNTHESIS AND DRUG PROFILE

H₁-antagonists with classical structure

Monoaminopropyl analogues

i. Unsaturated analogues

1. Triprolidine (Actidil)

Synthesis

Properties and uses: Triprolidine hydrochloride is a white crystalline powder, practically insoluble in ether, soluble in water and in ethanol. The activity is mainly confined to the geometric isomer in which the pyrrolidino-methyl group is trans to the 2-pyridyl group. Pharmacological studies confirm the high activity of triprolidine and the superiority of (E) over corresponding (Z) isomers as H₁-antagonists. In guinea pig ileum sites, the affinity of triprolidine (E) for H₁-receptors was more than 1000 times the affinity of its (Z) partner.

Assay: Dissolve the sample in a mixture of anhydrous acetic acid and acetic anhydride and titrate against 0.1 M perchloric acid using crystal violet solution as indicator.

Dose: Usual dose is 5–7.5 mg per day.

Dosage forms: Triprolidine HCl tablets I.P., Triprolidine tablets B.P.