ERRγ 1.3 μM (IC50)

Absorption, Distribution and Excretion
2-Ethylhexyl diphenyl phosphate was administered to rabbits at a dose of 0.625–2.50 mL/kg daily. …The phenol content (in all forms) detected in rabbits was …94%. …The phenol content detected in rabbit feces and urine was …74% and 19.5%, respectively. …2-Ethylhexyl diphenyl phosphate has low intestinal absorption. 2-Ethylhexyl diphenyl phosphate was administered to humans at a dose of 5 mL/kg daily. …The phenol content (in all forms) detected in humans was 96%. …The phenol content detected in human subjects' feces and urine was 83% and 13%, respectively. …2-Ethylhexyl diphenyl phosphate has low intestinal absorption. The metabolic pathway of 2-ethylhexyl diphenyl phosphate (EHDPP) in male rats was investigated. Following oral administration of (14)C-EHDPP, the drug was rapidly absorbed, with approximately 80% of the radioactive material excreted in urine and feces within the first 24 hours. Seven days later, 48% and 52% of the radioactive material were recovered in urine and feces, respectively. Due to low bile excretion (6% within 2 days), urine appears to be the primary route of excretion for EHDPP. Radioactive material was widely distributed in all tissues tested. Relatively high concentrations of radioactivity were observed in blood, liver, kidneys, and adipose tissue after 2 hours. Clearance of radioactive material from adipose tissue and liver was slightly delayed, but almost all radioactive material was cleared within 7 days. The major metabolites in urine were diphenyl phosphate (DPP) and phenol. p-Hydroxyphenyl phosphate (OH-DPP) and monophenyl phosphate (MPP) were also identified as minor metabolites.

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Metabolism / Metabolites
This study investigated the metabolic pathway of 2-ethylhexyl diphenyl phosphate (EHDPP) in male rats. Following oral administration of 14C-EHDPP, it was rapidly absorbed, with approximately 80% of the radioactive material excreted in urine and feces within 24 hours. The major metabolites in urine were diphenyl phosphate (DPP) and phenol. p-Hydroxyphenyl phosphate (OH-DPP) and monophenyl phosphate (MPP) were also identified as minor metabolites.

Toxicity Summary
Identification and Uses: Diphenyl-2-ethylhexyl phosphate is a liquid. It is used as a plasticizer in food packaging films, skinless sausage tubing films, and other meat packaging. This compound is also a key component of certain non-flammable hydraulic fluids used in large aircraft. Human Exposure and Toxicity: Researchers detected this chemical in indoor air and dust samples from nurseries and correlated its levels with the levels of corresponding metabolites in children's urine. In other studies, researchers administered diphenyl-2-ethylhexyl phosphate to humans. The results showed that the levels of phenol (in all forms) in human feces and urine were 96% and 83%, respectively. The chemical has low intestinal absorption in humans. Animal Studies: In a 90-day study, researchers fed diphenyl-2-ethylhexyl phosphate to rats. Changes in blood chemistry, liver, and adrenal glands were observed in all dose groups. In a single-generation rat reproductive study, the high-dose F1 generation pups showed reduced weight gain and decreased 21-day survival. In both parents and F1 generations, regardless of sex, the relative and absolute weights of the liver and adrenal glands increased in a dose-dependent manner. Mammalian cell mutation assays using the Fischer mouse lymphoma L5178Y cell line were negative. In microbial cell mutation assays, treatment with diphenyl phosphate (DPP) on *Salmonella typhimurium* TA-1535, TA-1537, TA-1538, TA-98, TA-100 and *Saccharomyces cerevisiae* D4, regardless of metabolic activation, did not reveal mutagenicity. In rat bone marrow chromosome studies, no statistically significant differences in chromosomal structural defects or number were found between the treated and control groups. The major metabolites detected in rat urine were diphenyl phosphate (DPP) and phenol. p-Hydroxyphenyl phosphate (OH-DPP) and monophenyl phosphate (MPP) were also identified as minor metabolites.

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Non-Human Toxicity Values
LC50 Rabbit intravenous injection: 218-272 mg/kg body weight
LD50 Rabbit dermal administration: >7940 mg/kg body weight
LC50 Rat inhalation: ≤3 mg/L 6 hours
LD50 Rabbit oral administration: >24000 mg/kg body weight
For more complete non-human toxicity data for diphenyl-2-ethylhexyl phosphate (6 items in total), please visit the HSDB record page.

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Toxicity Data
LC50 (rat) > 4,800 mg/m3/4h

[1]. Activation of Peroxisome Proliferator-Activated Receptor Gamma and Disruption of Progesterone Synthesis of 2-Ethylhexyl Diphenyl Phosphate in Human Placental Choriocarcinoma Cells: Comparison with Triphenyl Phosphate. Environ Sci Technol. 2017 Apr 4;51(7):4061-4068.

[2]. Organophosphate esters bind to and inhibit estrogen-related receptor γ in cells. Environmental Science & Technology Letters, 2018, 5(2): 68-73.

2-Ethylhexyl diphenyl phosphate is a pale yellow liquid, insoluble in water. (NTP, 1992)
Octecix is an aryl phosphate ester.

C20H27O4P

362.41

362.165

1241-94-7

14716

Liquid

1.1±0.1 g/cm3

421.2±18.0 °C at 760 mmHg

-30 °C

222.0±41.6 °C

0.0±1.0 mmHg at 25°C

1.522

6.64

0

4

11

25

365

0

CCCCC(CC)COP(=O)(OC1=CC=CC=C1)OC2=CC=CC=C2

CGSLYBDCEGBZCG-UHFFFAOYSA-N

InChI=1S/C20H27O4P/c1-3-5-12-18(4-2)17-22-25(21,23-19-13-8-6-9-14-19)24-20-15-10-7-11-16-20/h6-11,13-16,18H,3-5,12,17H2,1-2H3

2-ethylhexyl diphenyl phosphate

EHDPP; Octicizer

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.)