Oxyphenbutazone targets cyclooxygenase (COX) enzymes, inhibiting the production of prostaglandins involved in inflammation, pain, and fever. As an NSAID, it reduces inflammation by blocking the synthesis of pro-inflammatory prostaglandins. It also has antimicrobial activity against Mycobacterium tuberculosis, selectively killing non-replicating bacteria.

In Hep3B cells, orphenibuta can improve methotrexate's (MTX) anti-cancer efficacy [1]. Hep3B cells may be cytotoxically affected by co-treatment with oxyphenbutazone (2.5–7.5 µM; 48 hours) and MTX (0.25–1.0 µM) [1]. Liver cells can be repaired by orphenibuta [1].

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In vitro, Oxyphenbutazone acts as a COX inhibitor with anti-inflammatory activity. It also exhibits antimicrobial activity against Mycobacterium tuberculosis, selectively killing non-replicating bacteria. Its in vitro activity is assessed by measuring its effects on COX enzyme activity, prostaglandin production, and bacterial viability.

Combining oxyphenbutazone (70 mg/kg/week; oral; divided into two doses; for 13 weeks) with MTX (5.0 or 2.5 mg/kg/week; intraperitoneally) may have anticancer effects [1].

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In vivo activity of Oxyphenbutazone has been demonstrated in clinical use as an anti-inflammatory agent for various conditions. It has been used in the management of postoperative ocular inflammation, superficial eye injuries, and episcleritis when administered as eye drops. Its anti-inflammatory and analgesic effects are mediated through COX inhibition.

The in vitro enzyme assay for Oxyphenbutazone involves measuring its inhibitory activity against cyclooxygenase (COX) enzymes using purified enzyme preparations. These assays measure the conversion of arachidonic acid to prostaglandins in the presence of the compound. Inhibitory potency (IC50) is determined by assessing the reduction in prostaglandin production. The compound's activity against both COX-1 and COX-2 isoforms may be evaluated.

Cytotoxicity Assay[1]
Cell Types: Hep3B Cell
Tested Concentrations: 2.5 µM, 5 µM, 7.5 µM
Incubation Duration: 48 hrs (hours)
Experimental Results: Enhanced cytotoxicity of MTX.

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In vitro cellular assays for Oxyphenbutazone are performed using inflammatory cell models, such as macrophages or other immune cells. These assays measure the compound's ability to inhibit prostaglandin production and reduce inflammatory responses. Its antimicrobial activity against Mycobacterium tuberculosis is assessed using bacterial culture assays.

Animal/Disease Models: Wistar strain albino male rats (5-6 weeks; 150-220 g) [1]
Doses: 70 mg/kg/week (co-treatment with MTX 5.0 or 2.5 mg/kg/week)
Route of Administration: Oral ; once a week; taken in two divided doses; for 13 weeks.
Experimental Results: When combined with MTX, it has potential anti-cancer activity in rats.

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In vivo animal studies for Oxyphenbutazone are conducted in models of inflammation, such as carrageenan-induced paw edema or adjuvant-induced arthritis. These studies typically involve oral or topical administration of the compound, followed by assessment of inflammation, pain, and fever. The compound's anti-inflammatory and analgesic effects are evaluated in these models.

Absorption, Distribution and Excretion
... Oxyphenidazole binds extensively to plasma proteins, resulting in a plasma half-life of several days. Due to its binding to plasma proteins, which restricts glomerular filtration, and its relatively high PKA value, which favors passive reabsorption in the distal renal tubules, phenidazole is excreted only slowly in the urine. Metabolism/Metabolites It has been reported that during chronic administration, the oxidation of phenidazole can be detected by measuring the urinary excretion of three metabolites (oxyphenidazole, γ-hydroxyphenidazole, and P,γ-hydroxyphenidazole). Biological Half-Life In humans, the biological half-life of oxyphenidazole is approximately 2 days.

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Pharmacokinetic properties of Oxyphenbutazone are characterized by oral administration and systemic bioavailability. As an active metabolite of phenylbutazone, it is produced following phenylbutazone administration and contributes to its pharmacological effects. The compound is metabolized in the liver and excreted renally. Its pharmacokinetic profile supports its use as an anti-inflammatory agent.

Interactions
Some tricyclic compounds have been shown to delay the absorption of oxybutazolone in rats by prolonging gastric emptying time. ...Oxybutazolone may prolong prothrombin time in patients concurrently taking coumarin anticoagulants and may enhance the hypoglycemic effects of insulin and oral hypoglycemic agents. Serum oxybutazolone levels may increase when oxybutazolone is used concurrently with methanone in humans. Patients receiving these medications should be monitored for adverse reactions caused by oxybutazolone. Desipramine reduces the absorption of oxybutazolone. For more complete data on drug interactions of oxybutazolone (6 types in total), please visit the HSDB record page.

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Toxicology studies of Oxyphenbutazone have been conducted to evaluate its safety profile. As an NSAID, it is known to cause gastrointestinal, renal, and hematological adverse effects. It can induce bone marrow failure, which is a serious toxicity associated with its use. Its use has been limited due to these safety concerns.

[1]. Oxyphenbutazone promotes cytotoxicity in rats and Hep3B cellsvia suppression of PGE2 and deactivation of Wnt/β-catenin signaling pathway. Mol Cell Biochem. 2018 Jul;444(1-2):187-196.

[2]. Nonsteroidal anti-inflammatory drug sensitizes Mycobacterium tuberculosis to endogenous and exogenous antimicrobials. Proc Natl Acad Sci U S A. 2012 Oct 2;109(40):16004-11.

Butyloxyphenone is a metabolite of phenylbutanone, obtained by hydroxylation of the benzene ring at the 4-position. It was commonly used to treat pain, swelling, and stiffness caused by arthritis and gout (in its hydrated form), but was withdrawn from the market in 1984 due to its association with blood disorders and Stevens-Johnson syndrome. Butyloxyphenone has various pharmacological effects, including nonsteroidal anti-inflammatory drug (NSAID), non-narcotic analgesic, antipyretic, gout suppressant, drug metabolite, xenobiotic metabolite, antitumor drug, and antibacterial agent. It belongs to the pyrazolidine and phenolic compounds and is functionally related to phenylbutanone. Due to concerns about bone marrow suppression, butyloxyphenone was withdrawn from the Canadian market in March 1985. It is a nonsteroidal anti-inflammatory drug. Hydroxybutyrone eye drops were once used abroad to treat postoperative ocular inflammation, superficial ocular trauma, and scleritis. (From JAMA, Annals of Drug Evaluation, 1994, p. 2000) It was once used orally to treat rheumatic diseases such as ankylosing spondylitis, osteoarthritis, and rheumatoid arthritis, but this use is no longer considered appropriate due to the risk of serious hematologic adverse reactions. (From Martindale Pharmacopeia, 30th edition, p. 27) Mechanism of Action: ...It has significant anti-inflammatory effects in animals and similar efficacy in patients with rheumatoid arthritis and related diseases. ...It inhibits the biosynthesis of prostaglandins, uncouples oxidative phosphorylation, and inhibits the biosynthesis of ATP-dependent mucopolysaccharide sulfates in cartilage. /Phenylbutazone/ Therapeutic Uses: Nonsteroidal anti-inflammatory drug; Topical anti-inflammatory drug. Rheumatoid arthritis-related scleritis and uveitis can sometimes be successfully treated with hydroxybutazone.
Hydroxybutyronitrone has a mild uricosuric effect in animal and human studies, which may be attributed to one of its metabolites.
Hydroxybutyronitrone has a mild uricosuric effect in animal and human studies… The uricosuric effect is due to reduced reabsorption of uric acid by the renal tubules… Leading to significant retention of sodium and chloride, accompanied by decreased urine output… Reduced thyroid iodine uptake… Also inhibits enzymes of the Krebs cycle… /Phenoxybutyronitrone/
For more complete data on the therapeutic uses of phenoxybutyronitrone (7 in total), please visit the HSDB record page.

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Drug Warnings
…A 40-year-old male received a total of 1 gram of phenoxybutyronitrone over approximately 5 days within 2 months prior to admission; he died on the third day after the onset of these symptoms.
…Leukocytosis involved a 47-year-old male who received 1.9 grams of hydroxybutyronitrone for 2 weeks for fever within 13 months prior to admission. Upon admission, he received 0.6 grams of the drug; blood tests revealed he had leukemia, and he died approximately four months later. To minimize stomach irritation, it should always be taken immediately after meals or with a full glass of milk. It is claimed that oxyphenbutazone causes slightly less stomach irritation than phenbutazone. …To reduce stomach irritation, it should be taken in 3 or 4 divided doses after meals. For more complete data on oxyphenbutazone (8 in total), please visit the HSDB records page.

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Oxyphenbutazone is the active metabolite of phenylbutazone, an NSAID with anti-inflammatory, analgesic, and antipyretic properties. It also has antimicrobial activity, selectively killing non-replicating Mycobacterium tuberculosis. Oxyphenbutazone eye drops have been used for postoperative ocular inflammation and superficial eye injuries. Its use is limited due to its toxicity profile, including the potential to induce bone marrow failure.

C19H20N2O3

324.38

324.147

129-20-4

Oxyphenbutazone monohydrate;7081-38-1;Oxyphenbutazone-d9;1189693-23-9;Oxyphenbutazone-13C6

4641

White to off-white solid powder

1.241g/cm3

485.6ºC at 760mmHg

109-111°C

247.5ºC

4.7E-10mmHg at 25°C

1.61

3.623

1

3

5

24

454

0

HFHZKZSRXITVMK-UHFFFAOYSA-N

InChI=1S/C19H20N2O3/c1-2-3-9-17-18(23)20(14-7-5-4-6-8-14)21(19(17)24)15-10-12-16(22)13-11-15/h4-8,10-13,17,22H,2-3,9H2,1H3

4-butyl-1-(4-hydroxyphenyl)-2-phenylpyrazolidine-3,5-dione

G 29701. Oxyphenbutazone; G29701; G-29701

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : ~100 mg/mL (~308.29 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (7.71 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (7.71 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (7.71 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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 (Please use freshly prepared in vivo formulations for optimal results.)