WARNING: This product is for research use only, not for human or veterinary use.

MedKoo CAT#: 333053

CAS#: 80012-43-7 (free base)

Description: Epinastine is a second-generation antihistamine and mast cell stabilizer that is used in eye drops to treat allergic conjunctivitis. It is highly selective for the H1 receptor and does not cross the blood-brain-barrier.

Chemical Structure

CAS# 80012-43-7 (free base)

Theoretical Analysis

MedKoo Cat#: 333053
Name: Epinastine
CAS#: 80012-43-7 (free base)
Chemical Formula: C16H15N3
Exact Mass: 249.1266
Molecular Weight: 249.317
Elemental Analysis: C, 77.08; H, 6.06; N, 16.85

Price and Availability

Size Price Availability Quantity
50.0mg USD 450.0 2 Weeks
100.0mg USD 750.0 2 Weeks
200.0mg USD 1250.0 2 Weeks
500.0mg USD 2450.0 2 Weeks
1.0g USD 3450.0 2 Weeks
2.0g USD 5650.0 2 Weeks
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Related CAS #: 108929-04-0 (HCl)   80012-43-7 (free base)   127786-29-2 (HBr)    

Synonym: Epinastine; WAL 801; WAL-801; WAL801; brand names Alesion, Elestat, Purivist, Relestat.

IUPAC/Chemical Name: 9,13b-dihydro-1H-dibenzo[c,f]imidazo[1,5-a]azepin-3-amine


InChi Code: InChI=1S/C16H15N3/c17-16-18-10-15-13-7-3-1-5-11(13)9-12-6-2-4-8-14(12)19(15)16/h1-8,15H,9-10H2,(H2,17,18)


Appearance: Solid powder

Purity: >98% (or refer to the Certificate of Analysis)

Shipping Condition: Shipped under ambient temperature as non-hazardous chemical. This product is stable enough for a few weeks during ordinary shipping and time spent in Customs.

Storage Condition: Dry, dark and at 0 - 4 C for short term (days to weeks) or -20 C for long term (months to years).

Solubility: Soluble in DMSO

Shelf Life: >2 years if stored properly

Drug Formulation: This drug may be formulated in DMSO

Stock Solution Storage: 0 - 4 C for short term (days to weeks), or -20 C for long term (months).

HS Tariff Code: 2934.99.9001

Preparing Stock Solutions

The following data is based on the product molecular weight 249.317 Batch specific molecular weights may vary from batch to batch due to the degree of hydration, which will affect the solvent volumes required to prepare stock solutions.

Recalculate based on batch purity %
Concentration / Solvent Volume / Mass 1 mg 5 mg 10 mg
1 mM 1.15 mL 5.76 mL 11.51 mL
5 mM 0.23 mL 1.15 mL 2.3 mL
10 mM 0.12 mL 0.58 mL 1.15 mL
50 mM 0.02 mL 0.12 mL 0.23 mL

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1: Gumieniczek A, Berecka-Rycerz A, Hubicka U, Żmudzki P, Lejwoda K, Kozyra P. Photodegradation of the H1 Antihistaminic Topical Drugs Emedastine, Epinastine, and Ketotifen and ROS Tests for Estimations of Their Potent Phototoxicity. Pharmaceutics. 2020 Jun 17;12(6):560. doi: 10.3390/pharmaceutics12060560. PMID: 32560381; PMCID: PMC7356818.

2: Jha M, Moshirfar M. Epinastine. 2020 Jun 5. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan–. PMID: 32491470.

3: Jeong SH, Jang JH, Cho HY, Lee YB. Simultaneous measurement of epinastine and its metabolite, 9,13b-dehydroepinastine, in human plasma by a newly developed ultra-performance liquid chromatography-tandem mass spectrometry and its application to pharmacokinetic studies. Biomed Chromatogr. 2020 Sep;34(9):e4848. doi: 10.1002/bmc.4848. Epub 2020 Jun 25. PMID: 32302007.

4: Drugs and Lactation Database (LactMed) [Internet]. Bethesda (MD): National Library of Medicine (US); 2006–. Epinastine. 2020 Jan 20. PMID: 30000206.

5: Jeong SH, Jang JH, Cho HY, Lee YB. Pharmacokinetic Comparison of Epinastine Using Developed Human Plasma Assays. Molecules. 2020 Jan 3;25(1):209. doi: 10.3390/molecules25010209. PMID: 31947890; PMCID: PMC6983027.

6: Iwasa C, Zaima K, Metori K, Harikai N, Tanaka Y, Hamada J, Shinomiya K, Hayashi H. Transfer of epinastine to infants through human breast milk. Pharmazie. 2019 Dec 1;74(12):732-736. doi: 10.1691/ph.2019.9105. PMID: 31907112.

7: Minami T, Ishida W, Kishimoto T, Nakajima I, Hino S, Arai R, Matsunaga T, Fukushima A, Yamagami S. In vitro and in vivo performance of epinastine hydrochloride-releasing contact lenses. PLoS One. 2019 Jan 30;14(1):e0210362. doi: 10.1371/journal.pone.0210362. PMID: 30699147; PMCID: PMC6353132.

8: Mizoguchi T, Ozaki M, Ogino N. Efficacy of 0.05% epinastine and 0.1% olopatadine for allergic conjunctivitis as seasonal and preseasonal treatment. Clin Ophthalmol. 2017 Sep 27;11:1747-1753. doi: 10.2147/OPTH.S141279. PMID: 29026285; PMCID: PMC5627751.

9: Tagawa Y, Namba K, Nakazono Y, Iwata D, Ishida S. Evaluating the efficacy of epinastine ophthalmic solution using a conjunctivitis allergen challenge model in patients with birch pollen allergic conjunctivitis. Allergol Int. 2017 Apr;66(2):338-343. doi: 10.1016/j.alit.2016.08.011. Epub 2016 Oct 6. PMID: 27720602.

10: Roszkowski P, Maurin JK, Czarnocki Z. The enantioselective synthesis of (S)-(+)-mianserin and (S)-(+)-epinastine. Beilstein J Org Chem. 2015 Aug 28;11:1509-13. doi: 10.3762/bjoc.11.164. PMID: 26425208; PMCID: PMC4578372.

11: Ariga GG, Naik PN, Nandibewoor ST, Chimatadar SA. Study of fluorescence interaction and conformational changes of bovine serum albumin with histamine H₁ -receptor--drug epinastine hydrochloride by spectroscopic and time-resolved fluorescence methods. Biopolymers. 2015 Nov;103(11):646-57. doi: 10.1002/bip.22707. PMID: 26215421.

12: Fukushima A, Ebihara N. Efficacy of olopatadine versus epinastine for treating allergic conjunctivitis caused by Japanese cedar pollen: a double-blind randomized controlled trial. Adv Ther. 2014 Oct;31(10):1045-58. doi: 10.1007/s12325-014-0156-2. Epub 2014 Oct 1. PMID: 25269854; PMCID: PMC4209092.

13: Fujishima H, Ohashi Y, Takamura E. Efficacy of epinastine hydrochloride ophthalmic solution in allergic conjunctivitis by conjunctival cedar pollen allergen challenge. Ann Allergy Asthma Immunol. 2014 Oct;113(4):476-81. doi: 10.1016/j.anai.2014.07.007. Epub 2014 Aug 20. PMID: 25163405.

14: Semsettin B, Sinan E, Nigar V. Comparison of the effects of topical cyclosporine a 0.05%, cyclosporine a 2%, epinastine hydrochloride 0.05%, and prednisolone acetate 1% on allergic inflammation in an experimental allergic conjunctivitis model. Cornea. 2013 Nov;32(11):1465-9. doi: 10.1097/ICO.0b013e3182a3655d. PMID: 24055903.

15: Suzuki Y, Inoue T, Yamamoto A, Sugimoto Y. Prophylactic effects of the histamine H1 receptor antagonist epinastine and the dual thromboxane A2 receptor and chemoattractant receptor-homologous molecule expressed on Th2 cells antagonist ramatroban on allergic rhinitis model in mice. Biol Pharm Bull. 2011;34(4):507-10. doi: 10.1248/bpb.34.507. PMID: 21467637.

16: Watanabe N, Nakagawa T, Sano Y, Makino S. [Cautions in usage of generic epinastine]. Arerugi. 2011 Jan;60(1):51-2. Japanese. PMID: 21346407.

17: Gotoh M, Hashiguchi K, Okubo K. Efficacy of epinastine hydrochloride for antigen-provoked nasal symptoms in subjects with orchard grass pollinosis. Allergol Int. 2011 Mar;60(1):69-77. doi: 10.2332/allergolint.10-OA-0219. Epub 2011 Dec 25. PMID: 21173568.

18: Packham R, Walker RJ, Holden-Dye L. The effect of a selective octopamine antagonist, epinastine, on pharyngeal pumping in Caenorhabditis elegans. Invert Neurosci. 2010 Nov;10(1):47-52. doi: 10.1007/s10158-010-0107-9. Epub 2010 Oct 22. PMID: 20967561.

19: Yilinuer H, Yamaoka J, Kawana S. Effect of epinastine hydrochloride on murine self-scratching behavior after skin-scratching stimulation. Arch Dermatol Res. 2010 Jan;302(1):19-26. doi: 10.1007/s00403-009-1006-y. Epub 2009 Nov 24. PMID: 19937255.

20: Pradhan S, Abhishek K, Mah F. Epinastine: topical ophthalmic second generation antihistamine without significant systemic side effects. Expert Opin Drug Metab Toxicol. 2009 Sep;5(9):1135-40. doi: 10.1517/17425250903117284. PMID: 19630694.