Azelastine (Azelastinum) is a phthalazine derivative, and is an histamine antagonist and mast cell stabilizer.

Azelastine hydrochloride (Astelin) is a phthalazinone derivative with antihistaminergic activity.

(S)-Azelastine hydrochloride, an antihistamine, has been shown to down-regulate H1R, M1R and M3R levels. It has also been shown to inhibit proliferation of HNEpC.

(R)-Azelastine is an antihistamine which has been shown to down-regulate H1R, M1R and M3R levels. This compound has also been shown to inhibit HNEpC proliferation.

(S)-Azelastine is an antihistamine which has been shown to down-regulate H1R, M1R and M3R levels. This compound has also been shown to inhibit HNEpC proliferation.

(R)-Azelastine hydrochloride is an antihistamine which has been shown to down-regulate H1R, M1R and M3R levels. This compound has also been shown to inhibit HNEpC proliferation.

Desmethylazelastine, the primary active metabolite of Azelastine, undergoes oxidative metabolism via the cytochrome P450 enzyme system, exhibits a 97% protein binding rate, and has an elimination half-life of 54 hours. Azelastine, an orally active, selective, and high-affinity histamine H1-receptor antagonist, is utilized in the research of allergic rhinitis, asthma, diabetic hyperlipidemia, and SARS-CoV-2 [1] [2] [3] [4] [5].