药物化合物包括碳、氢和其他元素的稳定重同位素，在药物开发过程中主要作为定量示踪剂。由于氘化可能会影响药物的药代动力学和代谢特性，因此值得关注[1]。

Absorption, Distribution and Excretion
Following oral administration of a single 5g dose of sodium phenylbutyrate, the Cmax was 195-218 µg/mL under fasting conditions and the Tmax was one hour. The effect of food on drug absorption is unknown.
Approximately 80–100% of the dose was excreted by the kidneys within 24 hours as the conjugation product, phenylacetylglutamine. For each gram of sodium phenylbutyrate administered, it is estimated that between 0.12–0.15 grams of phenylacetylglutamine nitrogen are produced.

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Metabolism / Metabolites
The major sites for metabolism of sodium phenylbutyrate are the liver and kidney. Phenylbutyric acid is rapidly metabolized to phenylacetate via beta-oxidation. Phenylacetate is conjugated with phenylacetyl-CoA, which in turn combines with glutamine via acetylation to form phenylacetylglutamine.

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Biological Half-Life
Following oral administration of a single 5g dose of sodium phenylbutyrate, the elimination half-life of phenylbutyric acid ranged from 0.76 to 0.77 hours.

Hepatotoxicity
While the urea cycle disorders are caused by deficiencies of hepatic enzymes responsible for the elimination of nitrogen, patients generally present with hyperammonemia without other features or biochemical evidence of hepatic injury. Thus, serum aminotransferase, alkaline phosphatase and bilirubin levels are generally normal or only mildly elevated. Newborns presenting with hyperammonemia may have hepatomegaly but other, non-urea cycle, liver function is normal as is hepatic histology. Phenylbutyrate can help to lower ammonia levels acutely and manage to keep them in the normal or near normal range, but generally does not affect other liver functions. In open label studies, a small proportion of patients (particularly with ornithine transcarbamylase [OTC] deficiency) have had ALT or AST elevations, but these have generally been attributed to the underlying condition or its complications. Phenylbutyrate has not been linked to instances of clinically apparent liver injury with jaundice.
Likelihood score: E (unlikely cause of clinically apparent liver injury, but experience with its use is limited).

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Protein Binding
When co-administered with tauroursodeoxycholic acid as a combination product, the _in vitro_ plasma protein binding of phenylbutyric acid is 82%.

[1]. Impact of Deuterium Substitution on the Pharmacokinetics of Pharmaceuticals. Ann Pharmacother. 2019 Feb;53(2):211-216.

[2]. Enhanced growth inhibition by combination differentiation therapy with ligands of peroxisome proliferator-activated receptor-gamma and inhibitors of histone deacetylase in adenocarcinoma of the lung. Clin Cancer Res. 2002 Apr;8(4):1206-12.

[3]. Sodium phenylbutyrate abrogates African swine fever virus replication by disrupting the virus-induced hypoacetylation status of histone H3K9/K14. Virus Res. 2017 Oct 15242:24-29.

[4]. 4-Phenylbutyric acid protects against lipopolysaccharide-induced bone loss by modulating autophagy in osteoclasts. Biochem Pharmacol. 2018 May151:9-17.

4-phenylbutyric acid is a monocarboxylic acid the structure of which is that of butyric acid substituted with a phenyl group at C-4. It is a histone deacetylase inhibitor that displays anticancer activity. It inhibits cell proliferation, invasion and migration and induces apoptosis in glioma cells. It also inhibits protein isoprenylation, depletes plasma glutamine, increases production of foetal haemoglobin through transcriptional activation of the gamma-globin gene and affects hPPARgamma activation. It has a role as an EC 3.5.1.98 (histone deacetylase) inhibitor, an antineoplastic agent, an apoptosis inducer and a prodrug. It is functionally related to a butyric acid. It is a conjugate acid of a 4-phenylbutyrate.
Phenylbutyric acid is a fatty acid and a derivative of [butyric acid] naturally produced by colonic bacteria fermentation. It demonstrates a number of cellular and biological effects, such as relieving inflammation and acting as a chemical chaperone. It is used to treat genetic metabolic syndromes, neuropathies, and urea cycle disorders.
Phenylbutyric acid is a Nitrogen Binding Agent. The mechanism of action of phenylbutyric acid is as an Ammonium Ion Binding Activity.
Phenylbutyrate and sodium benzoate are orphan drugs approved for the treatment of hyperammonemia in patients with urea cycle disorders, a series of at least 8 rare genetic enzyme deficiencies. The urea cycle is the major pathway of elimination of excess nitrogen including ammonia, and absence of one of the urea cycle enzymes often causes elevations in serum ammonia which can be severe, life-threatening and result in permanent neurologic damage and cognitive deficiencies. Both phenylbutyrate and sodium benzoate act by promoting an alternative pathway of nitrogen elimination. Neither phenylbutyrate nor sodium benzoate have been linked to cases of liver injury either in the form of serum enzyme elevations during therapy or clinically apparent acute liver injury.
4-Phenylbutyric acid has been reported in Streptomyces with data available.
See also: Sodium Phenylbutyrate (active moiety of); Glycerol Phenylbutyrate (is active moiety of).

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Drug Indication
Phenylbutyric acid is used for the treatment of various conditions, including urea cycle disorders, neonatal-onset deficiency, late-onset deficiency disease in patients with a history of hyperammonemic encephalopathy. Phenylbutyric acid must be combined with dietary protein restriction and, in some cases, essential amino acid supplementation. Phenylbutyric acid, as sodium phenylbutyrate, is used in combination with [tauroursodeoxycholic acid] to treat amyotrophic lateral sclerosis (ALS) in adults.

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Mechanism of Action
Sodium phenylbutyrate is the most commonly used salt used in drug products of phenylbutyric acid. Sodium phenylbutyrate is a pro-drug that rapidly metabolizes to phenylacetate. Phenylacetate is conjugated with phenylacetyl-CoA, which in turn combines with glutamine via acetylation to form phenylacetylglutamine. Phenylacetylglutamine is then excreted by the kidneys, thus providing an alternate mechanism of waste nitrogen excretion to the urea cycle. Phenylacetylglutamine is comparable to urea, as each molecule contains two moles of nitrogen.

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Pharmacodynamics
Phenylbutyric acid decreases elevated plasma ammonia glutamine levels in patients with urea cycle disorders. It increases waste nitrogen excretion in the form of phenylacetylglutamine. In the intestines, phenylbutyric acid was shown to reduce mucosal inflammation, regulate transepithelial fluid transport, and improve oxidative status. Some studies report antineoplastic properties of phenylbutyric acid, showing that phenylbutyric acid can promote growth arrest and apoptosis of cancer cells. It is suggested that phenylbutyric acid can act as an ammonia scavenger, chemical chaperone, and histone deacetylase inhibitor.

C10H8D4O2

168.23

168.109

461391-24-2

4-Phenylbutyric acid;1821-12-1

4775

Typically exists as solid at room temperature

47 - 49 °C

2.093

37.3

1

2

4

12

137

0

C([2H])(CC1=CC=CC=C1)(C([2H])([2H])C(O)=O)[2H]

OBKXEAXTFZPCHS-UHFFFAOYSA-N

InChI=1S/C10H12O2/c11-10(12)8-4-7-9-5-2-1-3-6-9/h1-3,5-6H,4,7-8H2,(H,11,12)

4-phenylbutanoic acid

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

注意: 如下所列的是一些常用的体内动物实验溶解配方，主要用于溶解难溶或不溶于水的产品（水溶度<1 mg/mL）。 建议您先取少量样品进行尝试，如该配方可行，再根据实验需求增加样品量。

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注射用配方1: DMSO : Tween 80： Saline = 10 : 5 : 85 (如： 100 μL DMSO → 50 μL Tween 80 → 850 μL Saline)
*生理盐水/Saline的制备：将0.9g氯化钠/NaCl溶解在100 mL ddH ₂ O中，得到澄清溶液。
注射用配方 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (如： 100 μL DMSO → 400 μL PEG300 → 50 μL Tween 80 → 450 μL Saline)
注射用配方 3: DMSO : Corn oil = 10 : 90 (如： 100 μL DMSO → 900 μL Corn oil)
示例: 以注射用配方 3 (DMSO : Corn oil = 10 : 90) 为例说明, 如果要配制 1 mL 2.5 mg/mL的工作液, 您可以取 100 μL 25 mg/mL 澄清的 DMSO 储备液，加到 900 μL Corn oil/玉米油中, 混合均匀。

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注射用配方 4: DMSO : 20% SBE-β-CD in Saline = 10 : 90 [如：100 μL DMSO → 900 μL (20% SBE-β-CD in Saline)]
*20% SBE-β-CD in Saline的制备（4°C，储存1周）：将2g SBE-β-CD (磺丁基-β-环糊精) 溶解于10mL生理盐水中，得到澄清溶液。
注射用配方 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (如： 500 μL 2-Hydroxypropyl-β-cyclodextrin (羟丙基环胡精)→ 500 μL Saline)
注射用配方 6: DMSO : PEG300 : Castor oil : Saline = 5 : 10 : 20 : 65 (如： 50 μL DMSO → 100 μL PEG300 → 200 μL Castor oil → 650 μL Saline)
注射用配方 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (如： 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
注射用配方 8: 溶解于Cremophor/Ethanol (50 : 50), 然后用生理盐水稀释。
注射用配方 9: EtOH : Corn oil = 10 : 90 (如： 100 μL EtOH → 900 μL Corn oil)
注射用配方 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (如： 100 μL EtOH → 400 μL PEG300 → 50 μL Tween 80 → 450 μL Saline)

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口服配方 1: 悬浮于0.5% CMC Na (羧甲基纤维素钠)
口服配方 2: 悬浮于0.5% Carboxymethyl cellulose (羧甲基纤维素)
示例: 以口服配方 1 (悬浮于 0.5% CMC Na)为例说明, 如果要配制 100 mL 2.5 mg/mL 的工作液, 您可以先取0.5g CMC Na并将其溶解于100mL ddH2O中，得到0.5%CMC-Na澄清溶液；然后将250 mg待测化合物加到100 mL前述 0.5%CMC Na溶液中，得到悬浮液。

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口服配方 3: 溶解于 PEG400 (聚乙二醇400)
口服配方 4: 悬浮于0.2% Carboxymethyl cellulose (羧甲基纤维素)
口服配方 5: 溶解于0.25% Tween 80 and 0.5% Carboxymethyl cellulose (羧甲基纤维素)
口服配方 6: 做成粉末与食物混合

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注意: 以上为较为常见方法，仅供参考， InvivoChem并未独立验证这些配方的准确性。具体溶剂的选择首先应参照文献已报道溶解方法、配方或剂型，对于某些尚未有文献报道溶解方法的化合物，需通过前期实验来确定（建议先取少量样品进行尝试），包括产品的溶解情况、梯度设置、动物的耐受性等。

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请根据您的实验动物和给药方式选择适当的溶解配方/方案：
1、请先配制澄清的储备液(如：用DMSO配置50 或 100 mg/mL母液(储备液));
2、取适量母液，按从左到右的顺序依次添加助溶剂，澄清后再加入下一助溶剂。以 下列配方为例说明 (注意此配方只用于说明，并不一定代表此产品 的实际溶解配方):
10% DMSO → 40% PEG300 → 5% Tween-80 → 45% ddH2O (或 saline);
假设最终工作液的体积为 1 mL, 浓度为5 mg/mL: 取 100 μL 50 mg/mL 的澄清 DMSO 储备液加到 400 μL PEG300 中，混合均匀/澄清；向上述体系中加入50 μL Tween-80，混合均匀/澄清；然后继续加入450 μL ddH2O (或 saline)定容至 1 mL；
3、溶剂前显示的百分比是指该溶剂在最终溶液/工作液中的体积所占比例;
4、 如产品在配制过程中出现沉淀/析出，可通过加热(≤50℃)或超声的方式助溶;
5、为保证最佳实验结果，工作液请现配现用！
6、如不确定怎么将母液配置成体内动物实验的工作液，请查看说明书或联系我们;
7、 以上所有助溶剂都可在 Invivochem.cn网站购买。