Azelastine Hydrochloride API: Micronized & Injectable Ophthalmic/Nasal Grades

Azelastine hydrochloride is an orally effective antihistamine useful in the treatment of asthma and nasal allergy. It appears to inhibit release of histamine, in addition to antagonizing its action.

Azelastine hydrochloride is the hydrochloride salt form of azelastine, a phthalazinone derivative with antihistaminergic activity. Azelastine hydrochloride exhibits histamine H1-receptor antagonist activity in isolated tissues, animal models, and humans. Azelastine hydrochloride nasal solution is administered as a racemic mixture, and no difference in pharmacologic activity was noted between the enantiomers in vitro studies. The major metabolite, desmethylazelastine, also possesses H1-receptor antagonist activity. It competes with histamine for the H1 receptor, thereby diminishing the actions of histamine on effector cells and decreasing the histamine-mediated symptoms of allergic reaction, such as bronchoconstriction, vasodilation, increased capillary permeability and spasmodic contractions of gastrointestinal smooth muscle.