Title: Acemetacin
CAS Registry Number: 53164-05-9
CAS Name: 1-(4-Chlorobenzoyl)-5-methoxy-2-methyl-1H-indole-3-acetic acid carboxymethyl ester
Additional Names: [[1-(4-chlorobenzoyl)-5-methoxy-2-methylindol-3-yl]acetoxy]acetic acid
Manufacturers' Codes: TV-1322
Trademarks: Acemix (Bioprogress); Emflex (Merck KGaA); Rantudil (Bayer); Solart (Bioindustria)
Molecular Formula: C21H18ClNO6
Molecular Weight: 415.82
Percent Composition: C 60.66%, H 4.36%, Cl 8.53%, N 3.37%, O 23.09%
Literature References: Deriv of indomethacin, q.v. Prepn: K. H. Boltze et al., DE 2234651; eidem, US 3910952 (1972, 1975 both to Troponwerke). Series of articles on chemistry, analysis, pharmacodynamics, toxicology and clinical trials: Arzneim.-Forsch. 30, 1313-1468 (1980). Toxicity data: H. Jacobi, H.-D. Dell, ibid. 1398.
Properties: Very fine pale yellow crystals from petr ether, mp 150-153°. LD50 in male, female mice, male, female rats (mg/kg): 55.5, 18.42, 24.2, 30.1 orally; 34.1, 51.1, 38.1, 28.3 i.v. (Jacobi, Dell).
Melting point: mp 150-153°
Toxicity data: LD50 in male, female mice, male, female rats (mg/kg): 55.5, 18.42, 24.2, 30.1 orally; 34.1, 51.1, 38.1, 28.3 i.v. (Jacobi, Dell)
Therap-Cat: Anti-inflammatory.
Keywords: Anti-inflammatory (Nonsteroidal); Arylacetic Acid Derivatives.
Acenaphthene Acenocoumarol Aceperone Acephate Acepromazine

Systematic (IUPAC) name
2-[2-[1-(4-chlorobenzoyl)-5-methoxy-2-methylindol-3-yl]acetyl]oxyacetic acid
Clinical data
AHFS/ International Drug Names
Legal status POM (UK)
CAS number 53164-05-9 YesY
ATC code M01AB11
PubChem CID 1981
ChemSpider 1904 YesY
UNII 5V141XK28X YesY
KEGG D01582 YesY
Chemical data
Formula C21H18ClNO6 
Mol. mass 415.82372 g/mol
 YesY (what is this?)  (verify)

Acemetacin is a non-steroidal anti-inflammatory drug, used for the treatment of osteoarthritis, rheumatoid arthritis, lower back pain, and relieving post-operative pain. It is manufactured by Merck under the tradename Emflex, and is available in the UK as a prescription-only drug. Other brand names for acemetacin include Rheutrop (Austria), Acemetadoc, Acephlogont, Azeat, Rantudil (Germany, Mexico, Portugal), Gamespir (Greece), Oldan, Reudol (Spain), Tilur (Switzerland), Ost-map (Egypt).

Acemetacin, a glycolic acid ester of indometacin, acts as a prodrug; in the body, it is metabolized to indometacin, which then acts as an inhibitor of cyclooxygenase, producing the anti-inflammatory effects. An advantage of acemetacin is that it reduces gastric damage when compared to indometacin.