Pharma & Specialty Chemical Standards

Bepotastine, IUPAC name 2-ethyl-3-[[4-(4-fluorophenyl)-1-piperazinyl]methyl]-1H-benzimidazole, is a second-generation H1 antihistamine with molecular formula C18H19FN4 (molecular weight 310.37 g/mol). Structurally, it belongs to the benzimidazole-piperazine class, featuring a fused benzimidazole core linked to a 4-fluorophenyl-substituted piperazine ring. It exhibits high water solubility (logP -0.2) and is a white crystalline solid. Therapeutically, it alleviates allergic rhinitis and urticaria. Its mechanism involves selective, competitive inhibition of histamine H1 receptors, with minimal sedative effects due to poor blood-brain barrier penetration. Metabolized via CYP3A4, it demonstrates high oral bioavailability and prolonged half-life (12–14 hours).