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Details

Stereochemistry ABSOLUTE
Molecular Formula C22H24ClN3O
Molecular Weight 381.898
Optical Activity UNSPECIFIED
Defined Stereocenters 1 / 1
E/Z Centers 0
Charge 0

SHOW SMILES / InChI
Structure of AZELASTINE, (R)-

SMILES

CN1CCC[C@H](CC1)N2N=C(CC3=CC=C(Cl)C=C3)C4=C(C=CC=C4)C2=O

InChI

InChIKey=MBUVEWMHONZEQD-GOSISDBHSA-N
InChI=1S/C22H24ClN3O/c1-25-13-4-5-18(12-14-25)26-22(27)20-7-3-2-6-19(20)21(24-26)15-16-8-10-17(23)11-9-16/h2-3,6-11,18H,4-5,12-15H2,1H3/t18-/m1/s1

HIDE SMILES / InChI

Molecular Formula C22H24ClN3O
Molecular Weight 381.898
Charge 0
Count
Stereochemistry ABSOLUTE
Additional Stereochemistry No
Defined Stereocenters 1 / 1
E/Z Centers 0
Optical Activity UNSPECIFIED

Azelastine (brand names AZEP, ASTEPRO, ASTELIN etc.) a phthalazine derivative, is an antihistamine and mast cell stabilizer available as a nasal spray for hay fever and as eye drops for allergic conjunctivitis. Azelastine is a potent antiallergic compound with histamine H1-receptor antagonist activity and a rapid onset and long duration of action. The major metabolite, desmethylazelastine, also exhibits H1- receptor antagonist activity. AZEP Nasal Spray is administered as a racemic mixture. The racemate, R- and S- enantiomers were equally potent at inhibiting eyelid histamine-induced oedema in rats, however the R-enantiomer was 2-fold less active at inhibiting eyeball histamine-induced oedema.

CNS Activity

Curator's Comment: Azelastine is systemically absorbed and can cross the blood–brain barrier. In mice, azelastine showed a definite central action. In rats, a high dose of 100 mg/kg azelastine produced a slight suppression of the paradoxical sleep.

Approval Year

TargetsConditions

Conditions

ConditionModalityTargetsHighest PhaseProduct
Primary
ASTELIN

Approved Use

Astelin Nasal Spray is indicated for the treatment of the symptoms of seasonal allergic rhinitis such as rhinorrhea, sneezing, and nasal pruritus in adults and children 5 years and older, and for the treatment of the symptoms of vasomotor rhinitis, such as rhinorrhea, nasal congestion and postnasal drip in adults and children 12 years and older.

Launch Date

1996
Cmax

Cmax

ValueDoseCo-administeredAnalytePopulation
0.26 ng/mL
0.28 mg 2 times / day multiple, nasal
dose: 0.28 mg
route of administration: Nasal
experiment type: MULTIPLE
co-administered:
AZELASTINE plasma
Homo sapiens
population: UNKNOWN
age: ADULT
sex: UNKNOWN
food status: UNKNOWN
0.12 ng/mL
0.28 mg 2 times / day multiple, nasal
dose: 0.28 mg
route of administration: Nasal
experiment type: MULTIPLE
co-administered:
DESMETHYLAZELASTINE plasma
Homo sapiens
population: UNKNOWN
age: ADULT
sex: UNKNOWN
food status: UNKNOWN
3.9 ng/mL
2.2 mg 2 times / day multiple, oral
dose: 2.2 mg
route of administration: Oral
experiment type: MULTIPLE
co-administered:
AZELASTINE plasma
Homo sapiens
population: UNHEALTHY
age: ADULT
sex: UNKNOWN
food status: UNKNOWN
1.86 ng/mL
2.2 mg 2 times / day multiple, oral
dose: 2.2 mg
route of administration: Oral
experiment type: MULTIPLE
co-administered:
DESMETHYLAZELASTINE plasma
Homo sapiens
population: UNHEALTHY
age: ADULT
sex: UNKNOWN
food status: UNKNOWN
200 pg/mL
548 μg single, nasal
dose: 548 μg
route of administration: Nasal
experiment type: SINGLE
co-administered:
AZELASTINE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: MALE
food status: FASTED
23 pg/mL
548 μg single, nasal
dose: 548 μg
route of administration: Nasal
experiment type: SINGLE
co-administered:
DESMETHYLAZELASTINE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: MALE
food status: FASTED
409 pg/mL
822 μg single, nasal
dose: 822 μg
route of administration: Nasal
experiment type: SINGLE
co-administered:
AZELASTINE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: MALE
food status: FASTED
38 pg/mL
822 μg single, nasal
dose: 822 μg
route of administration: Nasal
experiment type: SINGLE
co-administered:
DESMETHYLAZELASTINE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: MALE
food status: FASTED
235 pg/mL
548 μg single, nasal
dose: 548 μg
route of administration: Nasal
experiment type: SINGLE
co-administered:
AZELASTINE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: MALE
food status: FASTED
24 pg/mL
548 μg single, nasal
dose: 548 μg
route of administration: Nasal
experiment type: SINGLE
co-administered:
DESMETHYLAZELASTINE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: MALE
food status: FASTED
0.55 ng/mL
1 mg single, oral
dose: 1 mg
route of administration: Oral
experiment type: SINGLE
co-administered:
AZELASTINE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: MALE
food status: FASTED
2.6 ng/mL
4 mg single, oral
dose: 4 mg
route of administration: Oral
experiment type: SINGLE
co-administered:
AZELASTINE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: MALE
food status: FASTED
1.1 ng/mL
2 mg single, oral
dose: 2 mg
route of administration: Oral
experiment type: SINGLE
co-administered:
AZELASTINE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: MALE
food status: FASTED
AUC

AUC

ValueDoseCo-administeredAnalytePopulation
5122 pg × h/mL
548 μg single, nasal
dose: 548 μg
route of administration: Nasal
experiment type: SINGLE
co-administered:
AZELASTINE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: MALE
food status: FASTED
2131 pg × h/mL
548 μg single, nasal
dose: 548 μg
route of administration: Nasal
experiment type: SINGLE
co-administered:
DESMETHYLAZELASTINE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: MALE
food status: FASTED
9312 pg × h/mL
822 μg single, nasal
dose: 822 μg
route of administration: Nasal
experiment type: SINGLE
co-administered:
AZELASTINE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: MALE
food status: FASTED
3824 pg × h/mL
822 μg single, nasal
dose: 822 μg
route of administration: Nasal
experiment type: SINGLE
co-administered:
DESMETHYLAZELASTINE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: MALE
food status: FASTED
6122 pg × h/mL
548 μg single, nasal
dose: 548 μg
route of administration: Nasal
experiment type: SINGLE
co-administered:
AZELASTINE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: MALE
food status: FASTED
2615 pg × h/mL
548 μg single, nasal
dose: 548 μg
route of administration: Nasal
experiment type: SINGLE
co-administered:
DESMETHYLAZELASTINE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: MALE
food status: FASTED
12.17 ng × h/mL
1 mg single, oral
dose: 1 mg
route of administration: Oral
experiment type: SINGLE
co-administered:
AZELASTINE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: MALE
food status: FASTED
38.6 ng × h/mL
4 mg single, oral
dose: 4 mg
route of administration: Oral
experiment type: SINGLE
co-administered:
AZELASTINE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: MALE
food status: FASTED
28.24 ng × h/mL
2 mg single, oral
dose: 2 mg
route of administration: Oral
experiment type: SINGLE
co-administered:
AZELASTINE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: MALE
food status: FASTED
T1/2

T1/2

ValueDoseCo-administeredAnalytePopulation
20 h
2.2 mg 2 times / day multiple, oral
dose: 2.2 mg
route of administration: Oral
experiment type: MULTIPLE
co-administered:
AZELASTINE plasma
Homo sapiens
population: UNHEALTHY
age: ADULT
sex: UNKNOWN
food status: UNKNOWN
45 h
2.2 mg 2 times / day multiple, oral
dose: 2.2 mg
route of administration: Oral
experiment type: MULTIPLE
co-administered:
DESMETHYLAZELASTINE plasma
Homo sapiens
population: UNHEALTHY
age: ADULT
sex: UNKNOWN
food status: UNKNOWN
17.3 h
1 mg single, oral
dose: 1 mg
route of administration: Oral
experiment type: SINGLE
co-administered:
AZELASTINE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: MALE
food status: FASTED
18.1 h
4 mg single, oral
dose: 4 mg
route of administration: Oral
experiment type: SINGLE
co-administered:
AZELASTINE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: MALE
food status: FASTED
21.4 h
2 mg single, oral
dose: 2 mg
route of administration: Oral
experiment type: SINGLE
co-administered:
AZELASTINE plasma
Homo sapiens
population: HEALTHY
age: ADULT
sex: MALE
food status: FASTED
Funbound

Funbound

ValueDoseCo-administeredAnalytePopulation
5%
AZELASTINE plasma
Homo sapiens
16%
AZELASTINE plasma
Homo sapiens
12%
AZELASTINE plasma
Homo sapiens
PubMed

PubMed

TitleDatePubMed
Simultaneous enantioselective separation of azelastine and three of its metabolites for the investigation of the enantiomeric metabolism in rats. I. Liquid chromatography-ionspray tandem mass spectrometry and electrokinetic capillary chromatography.
2003 Aug 15
Patents

Patents

Sample Use Guides

In Vivo Use Guide
Curator's Comment: To male Wistar rats one single dose of 50 mg/kg AZELASTINE, (R)- was applied orally (by oral gavage): https://www.ncbi.nlm.nih.gov/pubmed/12906914
Adults and children aged 5 years and over:Each spray contains 125 ug of azelastine (as hydrochloride).One spray into each nostril twice daily as necessary (equivalent to a daily dose of 0.50 mg azelastine
Route of Administration: Nasal
In Vitro Use Guide
Curator's Comment: Sensitized cultured human mast cells (CHMCs) were pretreated with various concentrations of azelastine or olopatadine for 5 minutes. Then, CHMCs were challenged with anti-immunoglobulin E (IgE) and the released mediators were quantitated.
The greatest inhibition of mediator release was seen when cultured human mast cells (CHMCs) were pretreated with 24 uM of azelastine.
Substance Class Chemical
Created
by admin
on Mon Mar 31 22:26:28 GMT 2025
Edited
by admin
on Mon Mar 31 22:26:28 GMT 2025
Record UNII
434T9969GH
Record Status Validated (UNII)
Record Version
  • Download
Name Type Language
1(2H)-PHTHALAZINONE, 4-((4-CHLOROPHENYL)METHYL)-2-((4R)-HEXAHYDRO-1-METHYL-1H-AZEPIN-4-YL)-
Preferred Name English
AZELASTINE, (R)-
Common Name English
Code System Code Type Description
CAS
143228-84-6
Created by admin on Mon Mar 31 22:26:28 GMT 2025 , Edited by admin on Mon Mar 31 22:26:28 GMT 2025
PRIMARY
PUBCHEM
12831280
Created by admin on Mon Mar 31 22:26:28 GMT 2025 , Edited by admin on Mon Mar 31 22:26:28 GMT 2025
PRIMARY
FDA UNII
434T9969GH
Created by admin on Mon Mar 31 22:26:28 GMT 2025 , Edited by admin on Mon Mar 31 22:26:28 GMT 2025
PRIMARY
Related Record Type Details
RACEMATE -> ENANTIOMER