Title: Oxaprozin
CAS Registry Number: 21256-18-8
CAS Name: 4,5-Diphenyl-2-oxazolepropanoic acid
Additional Names: b-(4,5-diphenyloxazol-2-yl)propionic acid
Manufacturers' Codes: Wy-21743
Trademarks: Alvo (Taisho); Daypro (Pfizer)
Molecular Formula: C18H15NO3
Molecular Weight: 293.32
Percent Composition: C 73.71%, H 5.15%, N 4.78%, O 16.36%
Literature References: First description of anti-inflammatory properties: K. Brown et al., Nature 219, 164 (1968). Prepn: FR 2001036 (1969 to Inst. Farm. Serono), C.A. 72, 66930w (1970); K. Brown, GB 1206403 and US 3578671 (1970, 1971 both to Wyeth). Biochemical properties: M. W. Whitehouse et al., Biochem. Pharmacol. 20, 2309 (1971). Metabolism: F. W. Janssen et al., Drug Metab. Dispos. 6, 465 (1978). Pharmacology: D. A. Shriver et al., Toxicol. Appl. Pharmacol. 42, 75 (1977); F. Awouters et al., J. Pharm. Pharmacol. 30, 41 (1978). Clinical studies: R. Jamar, J. Dequeker, Curr. Med. Res. Opin. 5, 433 (1978); J. A. Hubsher et al., J. Int. Med. Res. 7, 69 (1979); eidem, Arthritis Rheum. 25, S117 (1982). Protein binding and clearance: C. A. Homon et al., Agents Actions 12, 211 (1982). Symposium on pharmacology and clinical efficacy: Semin. Arthritis Rheum. 15, Suppl. 3, 1-107 (1986). Review of mechanism of action and clinical efficacy: F. Dallegri et. al., Expert Opin. Pharmacother. 6, 777-785 (2005).
Properties: Crystals from methanol, mp 160.5-161.5°. Slightly sol in alcohol. Insol in water. Partition coefficient (octanol/water): 4.8 (pH 7.4). pKa 4.3.
Melting point: mp 160.5-161.5°
pKa: pKa 4.3
Log P: Partition coefficient (octanol/water): 4.8 (pH 7.4)
Therap-Cat: Anti-inflammatory.
Keywords: Anti-inflammatory (Nonsteroidal); Arylpropionic Acid Derivatives.
Oxatomide Oxazepam Oxazidione Oxazolam Oxeladin

Systematic (IUPAC) name
3-(4,5-diphenyl-1,3-oxazol-2-yl)propanoic acid
Clinical data
Trade names Daypro
AHFS/Drugs.com monograph
MedlinePlus a693002
Pregnancy cat. C
Legal status Prescription Only (S4) (AU)
Routes Oral
Pharmacokinetic data
Bioavailability 95%
Protein binding 99%
Metabolism Liver—65% oxidation and 35% glucuronic acid conjugation. 5% are active phenolic metabolites.
Half-life 54.9 hours
CAS number 21256-18-8 YesY
ATC code M01AE12
PubChem CID 4614
DrugBank DB00991
ChemSpider 4453 YesY
KEGG D00463 YesY
Chemical data
Formula C18H15NO3 
Mol. mass 293.317 g/mol
 N (what is this?)  (verify)

Oxaprozin, also known as Oxaprozinum, (sold under the names: Daypro, Dayrun, Duraprox) is a non-steroidal anti-inflammatory drug (NSAID),[1] used to relieve the inflammation, swelling, stiffness, and joint pain associated with osteoarthritis and rheumatoid arthritis. Chemically, it is a propionic acid derivative. It is available in 600 mg tablets. Normal adult dosage is 1200 mg daily, not to exceed 1800 mg per day. Safety and efficacy has been established in children over 6 years with juvenile rheumatoid arthritis only, and there is an increased risk of adverse reactions in the elderly population.