Title: Clofibrate
CAS Registry Number: 637-07-0
CAS Name: 2-(4-Chlorophenoxy)-2-methylpropanoic acid ethyl ester
Additional Names: ethyl 2-(p-chlorophenoxy)-2-methylpropionate; ethyl p-chlorophenoxyisobutyrate
Trademarks: Amotril; Anparton (Sanwa); Apolan (Stockli); Artevil; Ateculon (Nippon Chemiphar); Ateriosan; Atheropront (Mack, Illert.); Atromidin; Atromid-S (Ayerst); Bioscleran (Pfleger); Claripex (Usafarma); Clobren-SF (Morishita); Clofinit (Gentili); CPIB; Hyclorate (Funai); Liprinal (BMS); Neo-Atromid; Normet (Gedeon Richter); Normolipol (Delagrange); Recolip (Benzon); Regelan (Zeneca); Serotinex; Sklerolip (Mepha); Skleromexe (L. Merckle); Sklero-Tablinen (Sanorania); Xyduril (Dorsch)
Molecular Formula: C12H15ClO3
Molecular Weight: 242.70
Percent Composition: C 59.39%, H 6.23%, Cl 14.61%, O 19.78%
Literature References: Prepn: W. G. M. Jones et al., GB 860303; eidem, US 3262850 (1961, 1966 both to I.C.I.). Clinical trials in the primary prevention of ischaemic heart disease: Br. Heart J. 40, 1069 (1978); Lancet 2, 379 (1980). Toxicity data: G. Metz et al., Arzneim.-Forsch. 27, 1173 (1977). Review of pharmacology: M. Chevais, Therapie 35, 5-22 (1980); of metabolism: M. N. Cayen, Rev. Drug Metab. Drug Interact. 3, 77-103 (1980); of toxicity studies: IARC Monographs 24, 39-58 (1980). Comprehensive description: M. M. A. Hassan, A. A. Elazzouny, Anal. Profiles Drug Subs. 11, 197-224 (1982).
Properties: Oil, bp20 148-150°. Practically insol in water. Misc with ethanol, acetone, chloroform, ether. LD50 in mice, rats (g/kg): 1.28, 1.65 orally (Metz).
Boiling point: bp20 148-150°
Toxicity data: LD50 in mice, rats (g/kg): 1.28, 1.65 orally (Metz)
Derivative Type: Mixture with androsterone
CAS Registry Number: 8075-95-4
Trademarks: Atromid (Ayerst)
Therap-Cat: Antilipemic.
Keywords: Antilipemic; Fibrates.
Clofibric Acid Cloflucarban Clofoctol Cloforex Clomacran

Systematic (IUPAC) name
ethyl 2-(4-chlorophenoxy)-2-methylpropanoate
Clinical data
AHFS/ Micromedex Detailed Consumer Information
Pregnancy cat. B1 (AU) C (US)
Legal status Discontinued (US)
Routes Oral
Pharmacokinetic data
Protein binding Variable, 92–97% at therapeutic concentrations
Metabolism Hydrolyzed to clofibric acid; hepatic glucuronidation
Half-life Highly variable; average 18–22 hours. Prolonged in renal failure
Excretion Renal, 95 to 99%
CAS number 637-07-0
ATC code C10AB01
PubChem CID 2796
DrugBank DB00636
ChemSpider 2694 YesY
KEGG D00279 YesY
Chemical data
Formula C12H15ClO3 
Mol. mass 242.698 g/mol
Physical data
Boiling point 148 °C (298 °F)
 YesY (what is this?)  (verify)

Clofibrate (tradename Atromid-S) is an organic compound. It is marketed as a fibrate. It is a lipid-lowering agent used for controlling the high cholesterol and triacylglyceride level in the blood. It increases lipoprotein lipase activity to promote the conversion of VLDL to LDL, and hence reduce the level of VLDL. It can increase the level of HDL as well.