Absorption, Distribution and Excretion
Most organophosphate compounds…are absorbed via the skin, conjunctiva, gastrointestinal tract, and lungs. /Organophosphate Compounds/

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Metabolism/Metabolites Rats were orally administered 100 mg/kg, and mice were intraperitoneally injected with 1000 mg/kg of 32P-labeled trimethyl phosphate. Dimethyl phosphate was primarily excreted in the urine. Only trace amounts of the parent compound were detected, and only in rats within 6 hours of administration. S-methylcysteine and S-methylcysteine N-acetate were also isolated. A small amount of S-methylglutathione was detected, presumably the initial methylation product of this series of metabolites… Trimethyl phosphate was metabolized faster in mice than in rats, but no evidence of further conversion to monomethyl phosphate was found in either animal group…

Toxicity Summary
Identification and Uses: Trimethyl phosphate (TMP) is a colorless liquid. It is used as a gasoline additive to control surface ignition and spark plug carbon buildup; a methylating agent, a chemical intermediate in the production of polymethyl polyphosphate; a flame-retardant solvent for paints and polymers; and a catalyst in the preparation of polymers and resins. Human Exposure and Toxicity: The neurotoxic effects of TMP include weakness and paralysis. Animal Studies: TMP is irritating to the rabbit eyes. In rabbits, oral or dermal administration can cause flaccid and spastic paralysis. TMP is neurotoxic in Peg dogs. After 4 weeks, neurotoxicity in jumping, tactile localization, and ataxia gait was observed. Electrophysiological tests showed prolonged neuromuscular impulse conduction latency after 9 weeks, followed by a decrease in the maximum conduction velocity of sensory fibers. Peripheral nerve fibers also exhibit abnormalities at this time, including paranodecal and internodecal swelling, paranodecal demyelination, and distal rupture. TMP can cause infertility in mice, rats, and rabbits. Trimethyl phosphate primarily affects epididymal sperm, possibly by influencing sperm motility. Trimethyl phosphate can cause azoospermia in male fruit flies. Larval testicular cell studies indicate that the chemically infertile effect of this chemical targets early primary spermatocytes. In mouse developmental studies, F1 male offspring were infertile or semi-infertile due to heritable chromosomal translocations. Therefore, trimethyl phosphate can cause chromosomal damage in mouse sperm cells. In NTP carcinogenicity studies, trimethyl phosphate was associated with the development of benign fibromas in the subcutaneous tissue of male Fischer rats. No evidence of carcinogenicity of this compound was found in female rats. Trimethyl phosphate is carcinogenic in female mice, inducing uterine/endometrial adenocarcinoma. No carcinogenicity of this compound was found in male mice. Ecotoxicity studies: Oral administration of trimethyl phosphate to Japanese quail resulted in a rapid decrease in the percentage of fertilized eggs within 10 days of the first dose. Another study reported that only 81% of eggs laid by male quails treated with trimethyl phosphate within 1 to 35 days were fertilized, significantly lower than the control group.

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Non-human toxicity values
Rabbit dermal LD50: 3388 mg/kg
Rat oral LD50: 840 mg/kg
Rabbit oral LD50: 1050 mg/kg
Mouse oral LD50: 1470 mg/kg
For more non-human toxicity values (complete data) for trimethyl phosphate (8 values in total), please visit the HSDB record page.

According to the U.S. Environmental Protection Agency (EPA), trimethyl phosphate may be carcinogenic. Trimethyl phosphate is a pale straw-colored liquid. Inhalation may irritate the respiratory tract. Vapors or the liquid may irritate the skin or eyes. Ingestion may irritate the gastrointestinal mucosa. Trimethyl phosphate is a trialkyl phosphate ester, a trimethyl ester of phosphoric acid. It is used as an insect attractant and a nuclear magnetic resonance chemical shift reference compound.

C3H9O4P

140.07

140.023

512-56-1

10541

Liquid
Colorless liquid

1.2±0.1 g/cm3

197.2±0.0 °C at 760 mmHg

-46 °C

83.7±38.8 °C

0.5±0.3 mmHg at 25°C

1.379

-0.52

0

4

3

8

82.4

0

COP(=O)(OC)OC

WVLBCYQITXONBZ-UHFFFAOYSA-N

InChI=1S/C3H9O4P/c1-5-8(4,6-2)7-3/h1-3H3

trimethyl phosphate

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: Please store this product in a sealed and protected environment, avoid exposure to moisture.

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 (713.93 mM)

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.)