Pharma & Specialty Chemical Standards

Alcaftadine, IUPAC name 2-amino-5-chloro-3-(2-methoxyethyl)pyridine, is a pyridine-based antiallergic agent with molecular formula C8H12ClN3O and molecular weight 201.45 g/mol. Its structure features a substituted pyridine ring with a 2-amino, 5-chloro, and 3-methoxyethyl substituent. Therapeutically, it is used as an ophthalmic solution for allergic conjunctivitis. Physicochemically, it exhibits low water solubility (logP ~1.5) and pKa ~7.5. Mechanistically, it acts as a selective histamine H1 receptor antagonist, inhibiting histamine-mediated allergic responses, while also stabilizing mast cells to prevent degranulation. Its lipophilic nature facilitates ocular penetration, enhancing efficacy in topical formulations.