Title: Flunisolide
CAS Registry Number: 3385-03-3
CAS Name: (6a,11b,16a)-6-Fluoro-11,21-dihydroxy-16,17-[(1-methylethylidene)bis(oxy)]pregna-1,4-diene-3,20-dione
Additional Names: 6a-fluoro-11b,16a,17,21-tetrahydroxypregna-1,4-diene-3,20-dione cyclic 16,17-acetal with acetone; 6a-fluoro-11b,21-dihydroxy-16a,17-isopropylidenedioxy-D1,4-pregnadiene-3,20-dione
Manufacturers' Codes: RS-3999
Trademarks: Aerobid (Forest); Bronalide (Syntex); Lunis (Valeas); Nasalide (Syntex); Rhinalar (Syntex); Synaclyn (Syntex); Syntaris (Syntex)
Molecular Formula: C24H31FO6
Molecular Weight: 434.50
Percent Composition: C 66.34%, H 7.19%, F 4.37%, O 22.09%
Literature References: Synthetic fluorinated corticosteroid related to prednisolone, q.v. Prepn using S. roseochromogenes: GB 933867 (1963 to Am. Cyanamid), C.A. 60, 3070f (1964). Prepn using Cunninghamella blakesleeana 8688b: H. J. Ringold, G. Rosenkranz, US 3124571; H. J. Ringold et al., US 3126375 (both 1964 to Syntex). Metabolism: N. I. Chu et al., Drug Metab. Dispos. 7, 81 (1979). Use in rhinitis: J. N. Sahay et al., Clin. Allergy 9, 17 (1979); J. K. Sarsfield, G. E. Thomson, Br. Med. J. 2, 95 (1979). Use in bronchial asthma: D. R. Webb et al., Ann. Allergy 42, 80 (1979). Clinical study in chronic asthma: R. G. Slavin et al., J. Allergy Clin. Immunol. 66, 379 (1980). Review of pharmacology and therapeutic efficacy: G. E. Pakes et al., Drugs 19, 397-411 (1980); of clinical studies with HFA formulation: S. Shafazand, G. Colice, Expert Opin. Pharmacother. 5, 1163-1173 (2004).
Derivative Type: 21-Acetate
CAS Registry Number: 4533-89-5
Manufacturers' Codes: RS-1320
Molecular Formula: C26H33FO7
Molecular Weight: 476.53
Percent Composition: C 65.53%, H 6.98%, F 3.99%, O 23.50%
Therap-Cat: Glucocorticoid; antiasthmatic.
Keywords: Antiallergic (Steroidal, Nasal); Antiasthmatic (Steroidal, Inhalant); Glucocorticoid.
Flunixin Flunoxaprofen Fluoboric Acid Fluocinolone Acetonide Fluocortin Butyl

Flunisolide ball-and-stick.png
Systematic (IUPAC) name
Clinical data
Trade names Aerobid
AHFS/Drugs.com monograph
MedlinePlus a681048
Legal status  ?
Routes Inhaled
Pharmacokinetic data
Protein binding 40% after oral inhalation
Half-life 1.8 hours
CAS number 3385-03-3 YesY
ATC code R01AD04 R03BA03
PubChem CID 82153
DrugBank DB00180
ChemSpider 74144 YesY
KEGG D00324 N
Synonyms 6α-Fluoro-11β,16α,17,21-tetrahydroxypregna-1,4-diene-3,20-dione acetone cyclic 16,17-acetal
Chemical data
Formula C24H31FO6 
Mol. mass 434.498 g/mol
 N (what is this?)  (verify)

Flunisolide (marketed as AeroBid, Nasalide, Nasarel) is a corticosteroid often prescribed as treatment for allergic rhinitis.[1] In the United Kingdom it was formerly marketed as Syntaris, but this was recently discontinued by the manufacturers.[2]

The principal mechanism of action of flunisolide is to activate glucocorticoid receptors, meaning it has an anti-inflammatory action.