Alcaftadine and Impurities
Alcaftadine N-Oxide



Alcatadine is an imidazolium benzazepine that is 6, 11-dihydro-5H-imidazepine [2, 1-b] [3] benzazepine, which is replaced by formyl at the third position and 1-methylpiperidine-4-methylene at the 11th position. An antihistamine used in the treatment of allergic conjunctivitis. It has the effect of H1 receptor antagonist and anti-allergic drug. It is an aldehyde, a piperidine, an imidazepine, and a tertiary amine. This drug was approved in July 2010.


For the prevention of itching associated with allergic conjunctivitis.

Associated Conditions

Conjunctivitis, Seasonal Allergic


Following bilateral topical ocular administration of alcaftadine ophthalmic solution, 0.25%, the mean plasma Cmax of alcaftadine was approximately 60 pg/mL and the median Tmax occurred at 15 minutes. Plasma concentrations of alcaftadine were below the lower limit of quantification (10 pg/mL) by 3 hours after dosing. The mean Cmax of the active carboxylic acid metabolite was approximately 3 ng/mL and occurred at 1 hour after dosing. Plasma concentrations of the carboxylic acid metabolite were below the lower limit of quantification (100 pg/mL) by 12 hours after dosing.

Mechanism of action

Alcaftadine is a H1 histamine receptor antagonist and inhibitor of the release of histamine from mast cells. Decreased chemotaxis and inhibition of eosinophil activation has also been demonstrated.

TARGET: Histamine H1 receptor

ACTIONS: antagonist


Alcaftadine synthesis 1

  1. WO9222551A1 / US5468743A.

Alcaftadine synthesis 2

  1. WO2014154620A1.
  2. WO2014087208A2.

Alcaftadine synthesis 3

  1. CN103408549A.
  2. WO2014083571A1.

Clinical Trial Information

NCT Number Phase Status Date Conditions Sponsor/Collaborators
NCT02308501 4 Completed 2015-10-21 Allergic Conjunctivitis ORA, Inc.
NCT00223951 3 Completed 2015-02-19 Allergic Conjunctivitis Vistakon Pharmaceuticals
NCT00889330 3 Completed 2015-02-18 Allergic Conjunctivitis Vistakon Pharmaceuticals
NCT01808768 4 Unknown status 2013-05-29 Allergic Conjunctivitis Starx Research Center, LLC
NCT00241319 3 Completed 2011-09-26 Allergic Conjunctivitis Vistakon Pharmaceuticals


Publication Date Title Journal
2012-03-01 New drugs 2012 part I. Nursing
2012-01-01 Alcaftadine for the prevention of itching associated with allergic conjunctivitis. The Annals of pharmacotherapy
2011-12-01 Histamine and H1-antihistamines: celebrating a century of progress. The Journal of allergy and clinical immunology
2011-12-01 Alcaftadine: a topical antihistamine for use in allergic conjunctivitis. Drugs of today (Barcelona, Spain : 1998)
2011-04-01 Clinical pharmacology of alcaftadine, a novel antihistamine for the prevention of allergic conjunctivitis. Journal of ocular pharmacology and therapeutics : the official journal of the Association for Ocular Pharmacology and Therapeutics