Xanthine oxidase (XO) (Ki = 0.6 nM)

At Ki and Ki' values of 0.6 nM and 3.1 nM, respectively, Febuxostat sodium exhibits a strong mixed-type suppression of the activity of pure bovine milk xanthine oxidase, showing inhibition of both the reduced and oxidized versions of the enzyme[1].

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The purine analogue, allopurinol, has been in clinical use for more than 30 years as an inhibitor of xanthine oxidase (XO) in the treatment of hyperuricemia and gout. As consequences of structural similarities to purine compounds, however, allopurinol, its major active product, oxypurinol, and their respective metabolites inhibit other enzymes involved in purine and pyrimidine metabolism. Febuxostat (TEI-6720, TMX-67) is a potent, non-purine inhibitor of XO, currently under clinical evaluation for the treatment of hyperuricemia and gout. In this study, we investigated the effects of febuxostat on several enzymes in purine and pyrimidine metabolism and characterized the mechanism of febuxostat inhibition of XO activity. Febuxostat displayed potent mixed-type inhibition of the activity of purified bovine milk XO, with Ki and Ki' values of 0.6 and 3.1 nM respectively, indicating inhibition of both the oxidized and reduced forms of XO. In contrast, at concentrations up to 100 muM, febuxostat had no significant effects on the activities of the following enzymes of purine and pyrimidine metabolism: guanine deaminase, hypoxanthine-guanine phosphoribosyltransferase, purine nucleoside phosphorylase, orotate phosphoribosyltransferase and orotidine-5'-monophosphate decarboxylase. These results demonstrate that febuxostat is a potent non-purine, selective inhibitor of XO, and could be useful for the treatment of hyperuricemia and gout [1].

In comparison to fructose+P rats, febuxostat sodium (5–6 mg/kg; or daily for 4 weeks) significantly lowers lomerular pressure, renal vasoconstriction, and afferent arteriolar area. In rats fed a normal diet, febuxostat treatment alone has no significant effects[2]. In 5/6 Nx (5/6 nephrectomy) rats with and without concurrent hyperuricemia, febuxostat sodium (3–4 mg/kg; po; daily for 4 weeks) combined with oxonic acid (750 mg/kg; oral gavage; daily for 4 weeks) prevents renal injury[3]. In ApoE− /− mice, Febuxostat sodium (2.5 mg/kg; po; daily for 12 weeks) decreases plaque formation, and in atherosclerotic animals, it lowers ROS levels in the aorta wall[4]. The antidepressant effect of fruxostat sodium (15.6 mg/kg; po; once daily for 21 days) is demonstrated by a substantial reduction in the immobility time in the forced swimming test (FST) in mice[5]. When administered in conjunction with doxorubicin, fruxostat sodium (10 mg/kg; po; daily for 21 days) significantly reduced nephrotoxicity indicators and inflammatory mediators, restored oxidative stress biomarker levels to normal, and inhibited the production of renal caspase-3[6].

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Increased fructose consumption is associated with hyperuricemia, metabolic syndrome, and renal damage. This study evaluated whether febuxostat (Fx), an investigational nonpurine, and selective xanthine oxidase inhibitor, could alleviate the features of metabolic syndrome as well as the renal hemodynamic alterations and afferent arteriolopathy induced by a high-fructose diet in rats. Two groups of rats were fed a high-fructose diet (60% fructose) for 8 wk, and two groups received a normal diet. For each diet, one group was treated with Fx (5-6 mg.kg(-1).day(-1) in the drinking water) during the last 4 wk (i.e., after the onset of metabolic syndrome), and the other received no treatment (placebo; P). Body weight was measured daily. Systolic blood pressure and fasting plasma uric acid (UA), insulin, and triglycerides were measured at baseline and at 4 and 8 wk. Renal hemodynamics and histomorphology were evaluated at the end of the study. A high-fructose diet was associated with hyperuricemia, hypertension, as well as increased plasma triglycerides and insulin. Compared with fructose+P, fructose+Fx rats showed significantly lowered blood pressure, UA, triglycerides, and insulin (P < 0.05 for all comparisons). Moreover, fructose+Fx rats had significantly reduced glomerular pressure, renal vasoconstriction, and afferent arteriolar area relative to fructose+P rats. Fx treatment in rats on a normal diet had no significant effects. In conclusion, normalization of plasma UA with Fx in rats with metabolic syndrome alleviated both metabolic and glomerular hemodynamic and morphological alterations. These results provide further evidence for a pathogenic role of hyperuricemia in fructose-mediated metabolic syndrome. [2]

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Results: 5/6 Nx+OA+P rats developed hyperuricemia, renal vasoconstriction and glomerular hypertension in association with further aggravation of afferent arteriolopathy compared to 5/6 Nx+V+P. Fx prevented hyperuricemia in 5/6 Nx+OA+Fx rats and ameliorated proteinuria, preserved renal function and prevented glomerular hypertension in both 5/6 Nx+V+Fx and 5/6 Nx+OA+Fx groups. Functional improvement was accompanied by preservation of afferent arteriolar morphology and reduced tubulointerstitial fibrosis. Conclusion: Fx prevented renal injury in 5/6 Nx rats with and without coexisting hyperuricemia. Because Fx helped to preserve preglomerular vessel morphology, normal glomerular pressure was maintained even in the presence of systemic hypertension.[3]

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Atherosclerosis is a chronic inflammatory disease due to lipid deposition in the arterial wall. Multiple mechanisms participate in the inflammatory process, including oxidative stress. Xanthine oxidase (XO) is a major source of reactive oxygen species (ROS) and has been linked to the pathogenesis of atherosclerosis, but the underlying mechanisms remain unclear. Here, we show enhanced XO expression in macrophages in the atherosclerotic plaque and in aortic endothelial cells in ApoE(-/-) mice, and that febuxostat, a highly potent XO inhibitor, suppressed plaque formation, reduced arterial ROS levels and improved endothelial dysfunction in ApoE(-/-) mice without affecting plasma cholesterol levels. In vitro, febuxostat inhibited cholesterol crystal-induced ROS formation and inflammatory cytokine release in murine macrophages. These results demonstrate that in the atherosclerotic plaque, XO-mediated ROS formation is pro-inflammatory and XO-inhibition by febuxostat is a potential therapy for atherosclerosis. [4]

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Allopurinol and febuxostat expressed significant antidepressant like effect as indicated by reduction in the immobility period of mice in the FST as compared to control group. The effects of allopurinol and febuxostat were found to be comparable to that of fluoxetine. Conclusion: The results of the present study indicate that allopurinol and febuxostat possess significant antidepressant like activity. [5]

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Sildenafil and febuxostat protect against doxorubicin-induced nephrotoxicity; however the exact mechanism remains to be elucidated. The effect of sildenafil and febuxostat on doxorubicin-induced nephrotoxicity in rats was studied. Male rats were subdivided into nine groups. The 1st group served as normal control, the 2nd group received dimethylsulfoxide 50% (DMSO), the 3rd group received doxorubicin (3.5mg/kg, i.p.), twice weekly for 3 weeks. The next 3 groups received sildenafil (5mg/kg; p.o.), febuxostat (10mg/kg; p.o.) and their combination, respectively daily for 21 days. The last 3 groups received doxorubicin in combination with sildenafil, febuxostat or their combination. Nephrotoxicity was evaluated histopathologically by light microscopy and biochemically through measuring the following parameters, Kidney function biomarkers [serum levels of urea, creatinine and uric acid], oxidative stress biomarkers [kidney contents of glutathione reduced (GSH) and malondialdehyde (MDA)], The apoptotic marker namely; caspase-3 in kidney tissue and the inflammatory mediator tumor necrosis factor alpha (TNF-α). doxorubicin-induced a significant elevation in nephrotoxicity markers, expression of caspase-3 and caused induction of inflammation and oxidative stress. Histological changes in the kidney was tubular necrosis. Sildenafil and/or febuxostat administration with doxorubicin caused a significant decrease in nephrotoxicity markers and inflammatory mediators, restoration of normal values of oxidative stress biomarkers and hampering the expression of renal caspase-3. They also ameliorate histological changes induced by doxorubicin. sildenafil and febuxostat are promising protective agents against doxorubicin-nephrotoxicity through improving biochemical, inflammatory, histopathological and immunohistochemical alterations induced by doxorubicin[6].

Enzyme assays [1]
All enzyme assays were performed using a Hitachi spectrophotometer (model U-3200) with a 6-cell positioner with the cell temperature maintained at 25°C. For all assays, the final volumes of the reaction mixtures were 2.5 mL in a 3-mL cell with a 1.0-cm light path.

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XO ASSAY [1]
The assay was conducted as described previously (Osada et al., 1993). The reaction mixture contained 0.1 M sodium phosphate buffer (pH 7.4), xanthine (2.5–20 μM) and XO (1.1 μg protein). The reaction was started by addition of enzyme, and uric acid formation (xanthine→ uric acid) was followed at 292 nm. The enzyme activity was calculated as μmol uric acid formed per min per mg protein during the initial linear portion of the reaction. The molar extinction coefficient (Δɛ292) of uric acid used in the calculation was 10,923 M−1cm−1. When inhibition of XO activity by febuxostat was studied, concentrations of xanthine were varied from 2.5 to 20 μM, and concentrations of febuxostat from 0 to 1.5 nM were tested. Inhibition mechanism was determined from Lineweaver-Burk plots, and Ki and Ki' values were calculated from Dixon plots and 1/V-axis intercept replots, respectively.

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Guanine deaminase assay [1]
The assay procedure was based on the work of Lewis and Glantz (1974). The reaction mixture contained 0.2 M sodium phosphate buffer (pH 7.0), 15 μM guanine [a substrate concentration near the Michaelis constant of 12.5 μM (Glantz and Lewis, 1978)], and guanine deaminase (0.4 μg protein). After thorough mixing, consumption of guanine (guanine→ xanthine) was monitored at 246 nm. The enzyme activity was calculated as nmol xanthine formed per min per mg protein during the initial linear portion of the reaction. The molar extinction coefficient (Δɛ246) of xanthine used in the calculation was 5,662 M−1cm−1.

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HGPRT assay [1]
The assay procedure for HGPRT activity was a modification of the method of Giacomello and Salerno (1978). The reaction mixture contained 50 mM Tris-HCl buffer (pH 8.0), 2 mM MgCl2, 0.5 mM PRPP, 1 mM DTT, 10 μM hypoxanthine [a substrate concentration near the Michaelis constant of 7.7 μM (Giacomello and Salerno, 1978)], and HGPRT (7.1 μg protein). After thorough mixing, the increase in absorbance at 245 nm resulting from formation of inosine-5′-monophosphate (IMP) (hypoxanthine → IMP) was monitored. The enzyme activity was calculated as nmol IMP formed per min per mg protein during the initial linear portion of the reaction, using the molar extinction coefficient (Δɛ245) of 1,657 M−1cm−1 for IMP.

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PNP assay [1]
This assay was carried out utilizing the method described by Stoeckler and Parks (1985). The reaction mixture contained 0.5 M potassium phosphate buffer (pH 7.5), 50 μM guanosine [a substrate concentration near the Michaelis constant of 32 μM (Stoeckler and Parks, 1985)], 1 mM DTT, and PNP (0.8 mg protein). After thorough mixing, the decrease in absorbance at 258 nm resulting from the consumption of guanosine (guanosine → guanine) was monitored. The enzyme activity was calculated as μmol guanine formed per min per mg protein during the initial linear portion of the reaction. The molar extinction coefficient (Δɛ258) for guanine used in this calculation was 5,911 M−1cm−1.

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OPRT assay [1]
The OPRT activity was assayed utilizing a modification of the method of Lieberman et al. (1955). The reaction mixture contained 50 mM Tris-HCl (pH 8.0), 2 mM MgCl2, 1 mM DTT, 15 μM OA [a substrate concentration near the Michaelis constant of 15.4 μM (Shostak et al., 1990)], 0.5 mM PRPP and OPRT (4.7 μg protein). After thorough mixing, the decrease in optical density at 295 nm, reflecting consumption of OA (OA→ OMP), was monitored. The enzyme activity was calculated as nmol of OMP formed per min per mg protein during the initial linear portion of the reaction. The molar extinction coefficient (Δɛ295) for OMP (2,997 M−1cm−1) was used in the calculation of enzyme activity.

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OMPDC assay [1]
The OMPDC activity assay was performed employing a modification of the method of Lieberman et al. (1955). The reaction mixture contained 50 mM Tris-HCl (pH 8.0), 1 mM DTT, 10 μM OMP [a substrate concentration near the Michaelis constant of 6 μM (Shostak et al., 1990)], and OMPDC (10 μg protein). After thorough mixing, the decrease in absorbance at 285 nm, reflecting consumption of OMP [OMP → uridine-5′-monophosphate (UMP)] was monitored. The enzyme activity was calculated as nmol UMP formed per min per mg protein during the initial linear portion of the reaction. The molar extinction coefficient Δɛ285 for UMP (2,285 M−1cm−1) was used in the calculation of enzyme activity.

Four groups of male Sprague-Dawley rats (n = 10/group; 290–350 g) were studied over a period of 8 wk. Two groups (normal) received a regular diet and the other two groups (fructose) were fed a 60% fructose diet to induce development of the metabolic syndrome. Details on the composition of the diets are presented in Table 1. After 4 wk, febuxostat (Fx) was administered in the drinking water (50 mg/l; ∼5–6 mg·kg−1·day−1) for an additional 4 wk in one normal-diet group (normal+Fx) and one fructose-diet group (fructose+Fx). Respective placebo (P) control groups (normal+P and fructose+P) received no treatment, except for an additional amount of NaCl in the drinking water (5.84 mg/l, to maintain a salt concentration equivalent to that of the Fx-containing water) for 4 additional wk.[2]

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5–6 mg/kg/day

Rats

Absorption
After oral administration, about 85% of febuxostat is absorbed rapidly. Tmax ranges from 1 to 1.5 hours. Following once-daily oral administration, Cmax was approximately 1.6 ± 0.6 mcg/mL at a dose of 40 mg febuxostat and 2.6 ± 1.7 mcg/mL at a dose of 80 mg febuxostat. A high-fat meal decreased Cmax by 49% and AUC by 18%, but there were no clinically significant changes in the ability of febuxostat to decrease serum uric acid concentrations.

Route of Elimination
Febuxostat is eliminated via both hepatic and renal pathways. Following oral administration of 80 mg radiolabeled febuxostat, approximately 49% of the dose was recovered in the urine. In urine, about 3% of the recovered dose accounted for unchanged febuxostat, 30% accounted for the acyl glucuronide metabolite, 13% accounted for oxidative metabolites and their conjugates, and 3% accounted for unidentified metabolites. Approximately 45% of the total dose was recovered in the feces, where 12% of the dose accounted for the unchanged parent drug. About 1% accounted for the acyl glucuronide metabolite, 25% accounted for oxidative metabolites and their conjugates, and 7% accounted for unidentified metabolites.

Volume of Distribution
The apparent steady-state volume of distribution (Vss/F) of febuxostat ranges from 29 to 75 L, indicating a low to medium volume of distribution.

Clearance
Following oral administration of single doses of 10 to 240 mg, the mean apparent total clearance ranged from 10 to 12 L/h.

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Metabolism / Metabolites
Febuxostat is metabolized in the liver by UDP-glucuronosyltransferase (UGT) and Cytochrome P450 (CYP) enzymes, with the relative contribution of each enzyme isoform in the metabolism of febuxostat not fully elucidated. UGT1A1, UGT1A3, UGT1A9, and UGT2B7 mediate conjugation of febuxostat, which approximately accounts for 22–44% of the metabolism of the total dose administered, to produce the acyl-glucuronide metabolite. CYP1A2, CYP2C8, CYP2C9, and non-P450 enzymes are responsible for the oxidation reaction, which accounts for 2-8% of the metabolism of the dose. Oxidation reaction produces 67M-1, 67M-2, and 67M-4, which are pharmacologically active metabolites. 67M-1, 67M-2, and 67M-4 can further undergo glucuronidation and sulfation. Hydroxy metabolites are present in human plasma at much lower concentrations than the parent drug.

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Biological Half-Life
The apparent mean terminal elimination half-life of approximately 5 to 8 hours.

Hepatotoxicity
Liver test abnormalities have been reported to occur in 2% to 13% (average ~3.5%) of patients receiving febuxostat, but the levels are generally mild-to-moderate and self-limited. The height, nature and timing of these abnormalities have not been described. However, liver test elevations were the major reason for febuxostat discontinuation for adverse events (~2%) in clinical trials, despite the fact that no cases of jaundice or acute hepatitis were reported. Since its approval and more wide-scale use, there have been several individual case reports of liver injury attributed to febuxostat. Most cases have been marked by serum aminotransferase elevations without jaundice arising within days of starting febuxostat, including enzyme elevations in the setting of DRESS syndrome. At least one instance of a mixed-cholestatic hepatitis without immunoallergic features, arising after several months of treatment has been described. The product label for febuxostat lists hepatic steatosis, hepatitis and hepatomegaly as potential side effects. Furthermore, several cases of acute liver failure during febuxostat therapy have been reported to pharmacovigilance databases. Another unrelated, nonpurine xanthine oxidase inhibitor (benzbromarone) was not approved for use in the United States because of its potential for hepatic toxicity.

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Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
No information is available on the use of febuxostat during breastfeeding. Because febuxostat is more than 99% bound to plasma proteins, the amount in milk is likely to be low. Furthermore, oral bioavailability is only about 50%, so the amount an infant receives systemically is expected to be very small. If febuxostat is required by the mother, it is not a reason to discontinue breastfeeding; however, until more data become available, an alternate drug may be preferred.

◉ Effects in Breastfed Infants
Relevant published information was not found as of the revision date.

◉ Effects on Lactation and Breastmilk
Relevant published information was not found as of the revision date.

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Protein Binding Febuxostat is approximately 99.2% bound to plasma proteins, primarily to albumin. Plasma protein binding is constant over the concentration range achieved with 40 mg and 80 mg doses.

[1]. Selectivity of febuxostat, a novel non-purine inhibitor of xanthine oxidase/xanthine dehydrogenase. Life Sci, 2005, 76(16), 1835-1847.

[2]. Effects of febuxostat on metabolic and renal alterations in rats with fructose-induced metabolic syndrome. Am J Physiol Renal Physiol, 2008, 294(4), F710-F718.

[3]. Effect of febuxostat on the progression of renal disease in 5/6 nephrectomy rats with and without hyperuricemia. Nephron Physiol, 2008, 108(4), p69-p78.

[4]. Xanthine oxidase inhibition by febuxostat attenuates experimental atherosclerosis in mice. Sci Rep. 2014 Apr 1;4:4554.

[5]. Evaluation of effect of allopurinol and febuxostat in behavioral model of depression in mice. Indian J Pharmacol. 2013 May-Jun;45(3):244-7.

[6]. Ameliorative effects of sildenafil and/or febuxostat on doxorubicin-induced nephrotoxicity in rats. Eur J Pharmacol. 2017 Jun 15;805:118-124.

Pharmacodynamics
Febuxostat is a novel, selective xanthine oxidase/dehydrogenase inhibitor that works by decreasing serum uric acid in a dose-dependent manner. In healthy subjects, febuxostat decreased the mean serum uric acid and serum xanthine concentrations, as well as the total urinary uric acid excretion. Febuxostat at daily doses of 40-80 mg reduced the 24-hour mean serum uric acid concentrations by 40 to 55%. Closely related to the drug-induced reduction of serum uric acid levels and mobilization of urate crystals in tissue deposits, febuxostat is associated with gout flares. Unlike [allopurinol] and [oxypurinol], febuxostat has no inhibitory actions against other enzymes involved in purine and pyrimidine synthesis and metabolism, because it does not structurally resemble purines or pyrimidines.

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Mechanism of Action
Gout is a form of acute arthritis that is characterized by the accumulation of crystals of monosodium urate and urate crystals in or around a joint, leading to inflammation and persistent urate crystal deposition in bones, joints, tissues, and other organs that may exacerbate over time. Hyperuricemia is closely related to gout, whereby it may exist for many years before the first clinical attack of gout; thus, aberrated serum uric acid levels and hyperuricemia are believed to be the biochemical aberration involved in the pathogenesis of gout. Xanthine oxidoreductase (XOR) can act as a xanthine oxidase or xanthine dehydrogenase. In humans, it is a critical enzyme for uric acid production as it catalyzes the oxidation reaction steps from hypoxanthine to xanthine and from xanthine to uric acid in the pathway of purine metabolism. Febuxostat potently inhibits XOR, blocking both its oxidase and dehydrogenase activities. With high affinity, febuxostat binds to XOR in a molecular channel leading to the molybdenum-pterin active site, where [allopurinol] demonstrates relatively weak competitive inhibition. XOR is mainly found in the dehydrogenase form under normal physiological conditions; however, in inflammatory conditions, XOR can be converted into the xanthine oxidase form, which catalyzes reactions that produce reactive oxygen species (ROS), such as peroxynitrite. ROS contribute to vascular inflammation and alterations in vascular function. As febuxostat can inhibit both forms of XOR, it can inhibit ROS formation, oxidative stress, and inflammation. In a rat model, febuxostat suppressed renal ischemia-reperfusion injury by attenuating oxidative stress.

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Febuxostat is a 1,3-thiazolemonocarboxylic acid that is 4-methyl-1,3-thiazole-5-carboxylic acid which is substituted by a 3-cyano-4-(2-methylpropoxy)phenyl group at position 2. It is an orally-active, potent, and selective xanthine oxidase inhibitor used for the treatment of chronic hyperuricaemia in patients with gout. It has a role as an EC 1.17.3.2 (xanthine oxidase) inhibitor. It is an aromatic ether, a nitrile and a 1,3-thiazolemonocarboxylic acid.
Febuxostat is a non-purine xanthine oxidase (XO) inhibitor. In early 2008, febuxostat was granted marketing authorization by the European Commission for the treatment of chronic hyperuricemia and gout. In the following year, the FDA for approved febuxostat for use in the chronic management of hyperuricemia in adult patients with gout who have an inadequate response or intolerance to [allopurinol]. Gout is a form of arthritis that is caused by the accumulation of uric acid crystal in or around a joint, leading to inflammation and further deposition of uric acid crystal deposition in bones, joints, tissues, and other organs in the long term. Gout is closely associated with hyperuricemia. Febuxostat works by inhibiting the activity of an enzyme that is responsible for the synthesis of uric acid, thereby reducing serum uric acid levels. In February 2019, a black box warning for febuxostat was added, based on the findings of a post-market clinical study (the CARES trial) where there was an increased risk of cardiovascular (CV) fatal outcomes in patients with gout and known cardiovascular disease treated with febuxostat, when compared to those treated with allopurinol. The manufacturer and the FDA advise health professionals to limit the use of febuxostat to second-line therapy in patients who have inadequate response or intolerance to allopurinol, and to avoid the use of febuxostat in patients with cardiovascular diseases.

Febuxostat is a Xanthine Oxidase Inhibitor. The mechanism of action of febuxostat is as a Xanthine Oxidase Inhibitor.
Febuxostat is a newly introduced nonpurine xanthine oxidase inhibitor used for the treatment of gout. Chronic febuxostat therapy has been associated with minor serum aminotransferase elevations, but has yet to be linked to cases of clinically apparent acute liver injury.

Febuxostat is an orally available, non-purine inhibitor of xanthine oxidase with uric acid lowering activity. Upon oral administration, febuxostat selectively and noncompetitively inhibits the activity of xanthine oxidase, an enzyme that converts oxypurines, including hypoxanthine and xanthine, into uric acid. By inhibiting xanthine oxidase, uric acid production is reduced and serum uric acid levels are lowered. Febuxostat may provide protection against acute renal failure caused by the excessive release of uric acid that occurs upon massive tumor cell lysis resulting from the treatment of some malignancies.

FEBUXOSTAT is a small molecule drug with a maximum clinical trial phase of IV (across all indications) that was first approved in 2009 and is indicated for gout and hyperuricemia and has 7 investigational indications. This drug has a black box warning from the FDA.
A thiazole derivative and inhibitor of XANTHINE OXIDASE that is used for the treatment of HYPERURICEMIA in patients with chronic GOUT.

C16H15N2NAO3S

340.37255358696

338.07

1140907-13-6

Febuxostat;144060-53-7;Febuxostat-d9;1246819-50-0

53372975

Typically exists as solid at room temperature

0

6

5

23

454

0

CNBCRDKBNDTWPM-UHFFFAOYSA-M

InChI=1S/C16H16N2O3S.Na/c1-9(2)8-21-13-5-4-11(6-12(13)7-17)15-18-10(3)14(22-15)16(19)20;/h4-6,9H,8H2,1-3H3,(H,19,20);/q;+1/p-1

sodium;2-[3-cyano-4-(2-methylpropoxy)phenyl]-4-methyl-1,3-thiazole-5-carboxylate

TEI-6720 sodium TMX-67 sodiumTEI6720 sodium TMX67 sodium

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)

May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.

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Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)
*Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution.
Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)
Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil)
Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals).

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Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)]
*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.
Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline)
Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline)
Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline
Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil)
Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)

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Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium)
Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose
Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals).

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Oral Formulation 3: Dissolved in PEG400
Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose
Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose
Oral Formulation 6: Mixing with food powders

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Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.

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