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Oxaprozin is a non-steroidal antiinflammatory agent indicated for use in various forms of rheumatoid arthritis, osteoarthritis, and ankylosing spondylitis. A long T_1/2 allows once/twice daily dosing. Structurally it is somewhat unique, being a 3- substituted, rather than a 2-substituted propionic acid.

White Solid

Wyeth (United Kingdom)

antiparasitic

Oxaprozin is an anti-inflammatory drug. Oxaprozin was comparable to Aspirin (A687780).

ChEBI: A monocarboxylic acid that is a propionic acid derivative having a 4,5-diphenyl-1,3-oxazol-2-yl substituent at position 3. It is non-steroidal anti-inflammatory drug commonly used to relieve the pain and inflammatory responses associated with osteoarthrit s and rheumatoid arthritis.

Oxaprozin (Daypro) is approved for the treatment of osteoarthritis and rheumatoid arthritis. Its long halflife allows for once daily dosing.The most frequently reported adverse effects of this drug are nausea, vomiting, and dyspepsia.

A clean dry reactor of 20 gallon (91 liters) capacity was charged with pyridine (9.25 kg), benzoin (16.5 kg) and succinic anhydride (11.7 kg.). The reactor was purged with nitrogen and a nitrogen atmosphere was maintain throughout the process. The mixture was heated without agitation until it became liquid at 85°C. Agitation was commenced and the mixture was heated at 90°-95°C for 1.5 hours. A solution of ammonium acetate (12.0 kg) in glacial acetic acid (35.0 kg) was charged to the header of the reactor and added to the reaction mixture over 15 minutes, maintaining the temperature between 90° and 95°C. The container for the solution and the header were washed with glacial acetic acid (4.0 kg) and the washing liquid was added to the reaction mixture. The reaction mixture was held at 90°-95°C for 2 hours. The reaction mixture was cooled to 50°C and transferred via a line filter to a reactor of 50 gallon (227 liters) capacity. The first reactor, lines and filter were washed with glacial acetic acid (4.0 kg.) which was combined with the reaction mixture. The reaction mixture was heated with agitation to 90°-95°C over 30 minutes and water (21.0 kg.) was added maintaining the temperature at 90°-95°C. The reaction mixture was then cooled to 20°-25°C over 55 minutes by means of water in the jacket of the reactor and then cooled to 10°-15°C by means of brine in the jacket and left overnight. The product was filtered on a ceramic filter and sucked well dry. The product on the filter was washed with a prefiltered mixture of glacial acetic acid (25.5 kg.) and water (12.5 kg) and sucked well dry. Pre-filtered water (50.0 kg) and the filter cake were added to a reactor of 50 gallon (227 liters) capacity. The mixture was stirred at room temperature for 30 minutes and filtered on a ceramic filter and the product was sucked well dry. The product on the filter was washed twice with prefiltered water (10 kg each time) and sucked well dry. The product was then dried in a Mitchell oven at 80°C for 16-18 hours. The yield of crude β-(4,5diphenyloxazol-2-yl)propionic acid was 15.9 kg (69.8%). This material only just failed specification for acceptable purity because although TLC analysis showed only very faint trace impurities.
Recrystallisation of crude β-(4,5-Diphenyloxazol-2-yl)propionic acid Methanol (62.0 kg) was added to a reactor of 50 gallon capacity (227 liters). 15.9 kg of the crude oxazole above prepared was added with agitation. The mixture was heated to reflux. All the solid dissolved. The mixture was then cooled to 50°C and transferred to a reactor of 20 gallon (91 liters) capacity. The larger reactor and transfer lines were washed through with methanol at about 40°C twice (3 kg each time). The mixture was cooled over 1 hour 50 minutes with agitation, gradually at first, to 15°-20°C by means of cooling water on the jacket of the reactor. The product was then filtered on a ceramic filter and sucked well dry. The product on the filter was washed twice with methanol (5 kg each time) and sucked well dry. The wash liquors were combined with the filtration liquors and retained. The product from the filter was dried in an air oven at 55°-60°C for 18 hours. The yield of β-(4,5diphenyloxazol-2-yl)propionic acid was 12.1 kg. TLC investigation showed the product to be pure. Melting point 160.5°-161.5°C.
Another crop of product was obtained from the methanol liquors as follows. The liquors were added to a reactor of 20 gallon (91 liters) capacity and the solvent was distilled off for 9 hours until solid appeared. The mixture was then cooled to 15° to 20°C over 1 3/4 hours using cooling water in the jacket of the reactor. The mixture was cooled to 10°C using brine in the jacket and stirred at this temperature for 30 minutes. The product was then filtered on a ceramic filter and sucked well dry. The product on the filter was washed twice with methanol (5 kg each time) and sucked well dry. The product was dried in an air oven at 55°-60°C for 18 hours. The yield was 2.14 kg. This product may also have been acceptably pure but its purity was not investigated. It was therefore retained as crude product to be resubjected to recrystallisation with methanol. The yield for the recrystallisation was thus 12.1 kg from a consumption of 13.76 kg of crude product, that is 88%. The overall yield of pure product is 69.8% times 88%, that is, 61.4%.

Daypro (Searle);DURAPROX.

Antiinflammatory

Oxaprozin, 4,5-diphenyl-2-oxazolepropionic acid (Daypro),differs from the other members of this group in being anarylpropionic acid derivative. It shares the same propertiesand side effects of other members in this group. It is indicatedfor the short- and long-term management of OA andRA, administered as a once-daily dose of 600- to 1,200-mgdose because of its long duration of action.

Oxaprozin is well absorbed (100%) following oral administration, but maximum plasma concentrations are not reached until 3 to 5 hours following ingestion. Oxaprozin is an anti-inflammatory agent possessing a rapid onset of action and a prolonged duration of action. In both the carrageenan raw paw edema assay and analgetic tests, it was equipotent with aspirin. Oxaprozin has been associated with the appearance of rash and/or mild photosensitivity. Some patients experience an increased incidence of rash on sun-exposed skin during clinical testing.

Oxaprozine is a nonsteroidal anti-inflammatory drug used for the treatment of mild to moderate pain including rheumatoid arthritis and osteoarthritis. Oxaprozine shows slow elimination kinetics with an elimination half-life of about 24 h. It is given orally (600–1200 mg/d, maximum dose 1800 mg/d).

Poison by ingestion, intravenous, and intraperitoneal routes. Moderately toxic by subcutaneous route. An experimental teratogen. Experimental reproductive effects. An anti-inflammatory agent. When heated to decomposition it emits toxic fumes of NOx.

Store at -20°C