Ketotifen-13C-d3

Ketotifen-¹³C-d₃ is intended for use as an internal standard for the quantification of ketotifen by GC- or LC-MS. Ketotifen is a histamine H₁ receptor antagonist (K_i = 1.3 nM) and mast cell stabilizer.^1,2 It is selective for H₁ receptors over H₂ and H₃ receptors (K_is = 987 and 2,500 nM, respectively).¹ Ketotifen (50 and 100 μM) inhibits degranulation of rat peritoneal mast cells induced by compound 48/80 .² It inhibits the passive cutaneous anaphylaxis (PCA) reaction in rats by 54.6% when administered orally at a dose of 20 mg/kg.³ Ketotifen (30 mg/kg) inhibits the quick phase airway response in a rat ovalbumin-induced immediate airway response model.⁴ Formulations containing ketotifen have been used in the treatment of itching associated with allergic conjunctivitis.

1.Sharif, N.A., Xu, S.X., and Yanni, J.M.Olopatadine (AL-4943A): Ligand binding and functional studies on a novel, long acting H1-selective histamine antagonist and anti-allergic agent for use in allergic conjunctivitisJ. Ocul. Pharmacol. Ther.12(4)401-407(1996) 2.Baba, A., Tachi, M., Ejima, Y., et al.Anti-allergic drugs tranilast and ketotifen dose-dependently exert mast cell-stabilizing propertiesCell Physiol. Biochem.38(1)15-27(2016) 3.Nishikawa, Y., Shindo, T., Ishi, K., et al.Acrylamide derivatives as antiallergic agents. III. Synthesis and structure-activity relationships of N-[4-(4-diphenylmethyl-1-piperazinyl)butyl]- and N-[4-(4-diphenylmethylene-1-piperidyl)butyl]-3-heteroarylacry lamidesChem. Pharm. Bull. (Tokyo)37(3)684-687(1989) 4.Miyagawa, N., Iwasaki, H., Kato, T., et al.Two pharmacological phases in antigen-induced immediate airway response in ratsBiol. Pharm. Bull.32(12)2260-2264(2008)