Absorption, Distribution and Excretion
Five to six male Dow-Wistar rats were intraperitoneally injected with 0.3–0.42 mg/kg 14-C-aziridine (ethyleneimine) and sacrificed at 24 and 96 hours, respectively. In both cases, approximately 50% of the administered dose was excreted in the urine; a small amount (3–5%) was present in the feces and exhaled air. A small amount of the test substance itself was detected in the urine, with most of the radioactivity originating from unknown metabolites. The radioactive substance was distributed throughout the rats, with slight accumulation in the liver, intestines, cecum, spleen, and kidneys. …It rapidly penetrates the skin of animals, and its dermal toxicity is not reduced even if washed off within one minute of exposure. Metabolites/Metabolites When rats were intraperitoneally injected with (14)-ethyleneimine (0.30–0.42 mg/kg body weight), approximately half of the (14)C was excreted in the urine after 96 hours, and 2–6% was excreted in the feces. Only a small amount of (14)C in urine is ethyleneimine; the majority of (14)C in urine exists in various unidentified products. 3% to 5% of (14)C is excreted as CO2, and 1% to 3% as ethyleneimine.

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Biological half-life
No relevant report found; [TDR, page 688]

[1]. A versatile vector for gene and oligonucleotide transfer into cells in culture and in vivo: polyethylenimine. Proc Natl Acad Sci U S A. 1995;92(16):7297-301.

According to an independent committee of scientific and health experts, ethyleneimine may be carcinogenic. Stabilized ethyleneimine is a clear, colorless liquid with an ammonia-like odor. Its flash point is 12°F (approximately -11°C). It is less dense than water. It is flammable over a wide vapor-air concentration range. Its vapors irritate the skin, eyes, nose, and throat. Prolonged inhalation, skin absorption, or ingestion may lead to poisoning. It is carcinogenic. Its vapors are heavier than air. Exothermic polymerization may occur when heated or contaminated. If polymerization occurs inside a container, the container may violently rupture. Aziridine is a saturated organic heterocyclic monocyclic parent compound belonging to the aziridine class of compounds and azircyclic alkanes. It is an alkylating agent. It is the conjugate base of aziridineonium. Ethyleneimine has a wide range of uses, including in polymer products as well as adhesives and binders. Acute (short-term) inhalation of ethyleneimine can cause severe respiratory irritation and inflammation in humans, but symptoms may be delayed by several hours. Some symptoms of acute inhalation of ethyleneimine in humans include tearing and burning of the eyes, sore throat, increased nasal discharge, bronchitis, difficulty breathing, and pulmonary edema. Ethyleneimine is a potent foaming agent that can cause third-degree chemical burns to the skin. It is also corrosive to eye tissues, potentially causing permanent corneal opacity and conjunctival scarring. Low-concentration chronic (long-term) inhalation of ethyleneimine has been reported to have effects on the blood. The U.S. Environmental Protection Agency has not listed ethyleneimine as a carcinogen. Ethyleneimine is a monofunctional alkylating agent with potential antitumor activity. Ethyleneimine primarily reacts with guanine and adenine residues on DNA, alkylating DNA, thereby creating interstrand crosslinks and DNA breaks, interfering with DNA replication and cell division. (NCI04)
See also: Polyethyleneimine (note moved to); Ethoxylated aziridine homopolymer (note moved to)...See more...

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Mechanism of Action
Ethyleneimine is a classic alkylating agent with biological effects similar to β-chloroethylamine. /Ethyleneimine/
Ethyleneimine reacts with guanosine in aqueous solution to produce two identified products: 7-alkylguanosine with an imidazole ring-opening (80%) and intact 1-alkylguanosine (14%). Incubation of ethyleneimine with guanosine or deoxyguanosine (1 h, 37 °C) at pH 6.0 yields some intact 7-alkylated products. The half-lives of the imidazole ring-opening 7-alkylguanosine are 11, 5, and 2.8 min at pH 7.0 and 7.7, respectively, compared to 21 min at pH 7.7.
…Examples of directly acting mutagens include alkylating agents, such as…ethyleneimine…Directly acting carcinogens are typically carcinogenic at multiple sites and are effective against all species tested…

C2H5N

43.0678

43.042

9002-98-6

27233-25-6;9002-98-6

9033

Colorless to light yellow liquid

1.030 g/mL at 25 °C

250 °C(lit.)

59-60°C

>230 °F

n20/D 1.5290

-0.4

1

1

0

3

10.3

0

N1([H])C([H])([H])C1([H])[H]

NOWKCMXCCJGMRR-UHFFFAOYSA-N

InChI=1S/C2H5N/c1-2-3-1/h3H,1-2H2

aziridine

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: This product requires protection from light (avoid light exposure) during transportation and storage.

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

DMSO : ~50 mg/mL

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.)