Title: Betamethasone
CAS Registry Number: 378-44-9
CAS Name: (11b,16b)-9-Fluoro-11,17,21-trihydroxy-16-methylpregna-1,4-diene-3,20-dione
Additional Names: 9a-fluoro-16b-methylprednisolone; 16b-methyl-9a-fluoro-D1-hydrocortisone; 16b-methyl-9a-fluoroprednisolone; betadexamethasone; flubenisolone; b-methasone
Manufacturers' Codes: Sch-4831; NSC-39470
Trademarks: beta-Corlan; Becort (Rachelle); Betasolon; Betnelan (GSK); Celestene (Schering-Plough); Celestone (Schering-Plough); Dermabet (Taro); Visubeta
Molecular Formula: C22H29FO5
Molecular Weight: 392.46
Percent Composition: C 67.33%, H 7.45%, F 4.84%, O 20.38%
Literature References: Prepn: Taub et al., J. Am. Chem. Soc. 80, 4435 (1958); Oliveto et al., ibid. 6688; Taub et al., ibid. 82, 4012 (1960); US 3053865 (1962 to Merck & Co.); Amiard et al., US 3104246 (1963 to Roussel-UCLAF). Also prepared from hecogenin. Comprehensive description of the dipropionate ester: M. G. Ferrante, B. C. Rudy, Anal. Profiles Drug Subs. 6, 43-60 (1977).
Properties: Crystals from ethyl acetate, mp 231-234° (dec). [a]D +108° (acetone). uv max (methanol): 238 nm (e 15200).
Melting point: mp 231-234° (dec)
Optical Rotation: [a]D +108° (acetone)
Absorption maximum: uv max (methanol): 238 nm (e 15200)
Derivative Type: 21-Acetate
CAS Registry Number: 987-24-6
Trademarks: Betafluorene (Lepetit); Celestovet (Biokema)
Molecular Formula: C24H31FO6
Molecular Weight: 434.50
Percent Composition: C 66.34%, H 7.19%, F 4.37%, O 22.09%
Properties: Hexagonal prisms from acetone + ether, mp 205-208° (Taub); also reported as mp 196-201° (Oliveto). [a]D +140° (chloroform). uv max (methanol): 238 nm (e 14800).
Melting point: mp 205-208° (Taub); mp 196-201° (Oliveto)
Optical Rotation: [a]D +140° (chloroform)
Absorption maximum: uv max (methanol): 238 nm (e 14800)
Derivative Type: 17-Benzoate
CAS Registry Number: 22298-29-9
Manufacturers' Codes: W-5975
Trademarks: Bebate; Beben (Pfizer); Benisone (Warner-Chilcott); Euvaderm (Gecke); Flurobate (Texas Pharmacal); Uticort (Pfizer)
Molecular Formula: C29H33FO6
Molecular Weight: 496.57
Percent Composition: C 70.14%, H 6.70%, F 3.83%, O 19.33%
Properties: Crystals from acetone-ether, mp 225-228°. [a]D24 +63.5° (dioxane). Synthesis and activity: Ercoli et al., J. Med. Chem. 15, 783 (1972). See also Cullen, Curr. Ther. Res. 15, 243 (1973).
Melting point: mp 225-228°
Optical Rotation: [a]D24 +63.5° (dioxane)
Derivative Type: 17,21-Dipropionate
CAS Registry Number: 5593-20-4
Manufacturers' Codes: Sch-11460
Trademarks: Diproderm (Schering-Plough); Diprolene (Schering-Plough); Diprophos (Schering-Plough); Diprosis (Essex); Diprosone (Schering-Plough); Maxivate (Westwood); Rinderon-DP (Shionogi)
Molecular Formula: C28H37FO7
Molecular Weight: 504.59
Percent Composition: C 66.65%, H 7.39%, F 3.77%, O 22.20%
Properties: Powder, mp 170-179° (dec). [a]D26 +65.7° (dioxane). uv max (methanol): 238 nm (e 15700). Insol in water.
Melting point: mp 170-179° (dec)
Optical Rotation: [a]D26 +65.7° (dioxane)
Absorption maximum: uv max (methanol): 238 nm (e 15700)
Derivative Type: 17-Valerate
CAS Registry Number: 2152-44-5
Trademarks: Bedermin (Damor); Betnesol-V (GSK); Betneval (GSK); Betnovate (GSK); Bextasol (GSK); Celestan-V (Essex); Celestoderm-V (Schering-Plough); Dermosol (Iwaki); Dermovaleas (Valeas); Ecoval 70; Hormezon (Tobishi); Tokuderm (Nichiban); Valisone (Schering-Plough)
Molecular Formula: C27H37FO6
Molecular Weight: 476.58
Percent Composition: C 68.05%, H 7.83%, F 3.99%, O 20.14%
Properties: Needles from acetone + petr ether, mp 183-184°. [a]D +77° (dioxane). uv max: 239 nm (e 15920). NL 6406615 (1964 to Glaxo).
Melting point: mp 183-184°
Optical Rotation: [a]D +77° (dioxane)
Absorption maximum: uv max: 239 nm (e 15920)
Derivative Type: 21-Phosphate disodium salt
CAS Registry Number: 151-73-5
Additional Names: Betamethasone 21-(dihydrogen phosphate) disodium salt
Trademarks: Bentelan (GSK); Betnesol (GSK); Celestan (Essex); Durabetason (Durachemie); Vista-Methasone (Richard Daniel)
Molecular Formula: C22H28FNa2O8P
Molecular Weight: 516.40
Percent Composition: C 51.17%, H 5.47%, F 3.68%, Na 8.90%, O 24.79%, P 6.00%
Therap-Cat: Glucocorticoid.
Therap-Cat-Vet: Glucocorticoid.
Keywords: Glucocorticoid.
Betamipron beta-Myrcene beta-Peltatin beta-Phellandrene beta-Picoline

Systematic (IUPAC) name
(8S,9R,10S,11S,13S,14S,16S,17R)-9-fluoro- 11,17-dihydroxy-17-(2-hydroxyacetyl)-10,13,16-trimethyl- 6,7,8,9,10,11,12,13,14,15,16,17-dodecahydro- 3H-cyclopenta[a]phenanthren-3-one
Clinical data
Trade names Celestone
AHFS/ monograph
Pregnancy cat. C (US)
Legal status Prescription only
Routes Oral,Topical,IM
Pharmacokinetic data
Bioavailability  ?
Metabolism hepatic CYP3A4
Half-life 36-54 hours
Excretion Renal (in urine)
CAS number 378-44-9 YesY
ATC code A07EA04 C05AA05 D07AC01 H02AB01 R01AD06 R03BA04 S01BA06 S02BA07 S03BA03
PubChem CID 9782
DrugBank DB00443
ChemSpider 9399 YesY
UNII 9842X06Q6M YesY
KEGG D00244 YesY
Chemical data
Formula C22H29FO5 
Mol. mass 392.461
 YesY (what is this?)  (verify)

Betamethasone is a potent glucocorticoid steroid with anti-inflammatory and immunosuppressive properties. Unlike other drugs with these effects, betamethasone does not cause water retention. It is applied as a topical cream, ointment, foam, lotion or gel to treat itching. Betamethasone sodium phosphate is sometimes prescribed as an intramuscular injection (I.M) for itching from various ailments, including allergic reactions to poison ivy and similar plants.