Absorption, Distribution and Excretion
Male Sprague-Dawley rats were given a single ip injection (45 mg/kg) of radiolabeled 1-methyl-2-pyrrolidone. Plasma levels of radioactivity and cmpd were monitored for six hr and the results suggested a rapid distribution phase which was followed by a slow elimination phase. The major amount of label was excreted in the urine within 12 hr and accounted for approximately 75% of the labelled dose. ...
This study evaluated the toxicokinetics of N-((14)C)methylpyrrolidone (((14)C)NMP) after intravenous administration (0.1, 1, 10, 100, and 500 mg/kg, in saline solution) or topical application (20 and 40 uL/sq cm; 10 sq cm, neat) in haired male Sprague-Dawley rats. Whatever the dose, unchanged NMP was intensively distributed into the body with a volume of distribution of 69% of body weight. After this phase, unchanged NMP declined almost linearly with time for 3 to 4 hr after administration and then followed a mono-exponential function (t1/2 = 0.8 hr) for the three lowest doses. The maximal plasma level of 5-hydroxy-N-methylpyrrolidone (5-HNMP), the main metabolite, was reached 4 to 6 hr later for the three lowest doses and 8 to 24 hr later for the highest doses. These findings indicate that the elimination of NMP is governed by a saturable metabolism process. The Michaelis-Menten parameters estimated from plasma levels of unchanged NMP were 2 mM and 3.8 mg/hr, respectively. Between 4 and 10% of the administered doses were excreted in the urine as unchanged NMP. Urinary clearance of NMP (0.03 to 0.07 mL/min) indicates intensive tubular reabsorption. 5-HNMP was the main urinary metabolite and accounted for 42 to 55% of the administered doses. Its maximal urinary excretion occurred between 4 and 6 hr after administration of the three lowest doses and between 8 and 24 hr for the two highest doses. Urinary clearance (0.9 to 1.3 mL/min) was compatible with renal elimination by simple glomerular filtration.
Metabolism studies were performed using (14)C and tritium labeled N-methyl-2-pyrrolidinone in the rat. Male Sprague-Dawley rats were injected with labeled or unlabeled N-methyl-2-pyrrolidinone at 45 mg/kg body weight. Urine, feces, expired air, and bile were collected at various times between drug administration and sacrifice. For pharmacokinetic studies, serial blood samples were analyzed at times between 30 minutes and 6 hours post injection. HPLC of plasma N-methyl-2-pyrrlidinone indicated a rapid distribution phase followed by a slow elimination phase with a half life of approximately 7 hours for the (14)C and 10 hours for the tritium isotope. Urinary excretion accounted for approx 70% of the total dose within 12 hours, and a 2:1 ratio in the administered dose was maintained in the urine. The tissue distribution of the radiolabeled isomers showed similar patterns. The rank order of tissue accumulation from highest to lowest concentration was liver, intestine, testes, stomach, kidneys, lungs, brain, heart, pancreas, and spleen. The bladder, thyroid, and thymus showed minimal N-methyl-2-pyrrolidinone levels.
Six male volunteers were exposed for eight hours on four different days to 0, 10, 25, and 50 mg/cu m N-methyl-2-pyrrolidone. ... N-Methyl-2-pyrrolidone was absorbed through the respiratory tract and readily eliminated from the body, mainly by biotransformation to other compounds. ...
For more Absorption, Distribution and Excretion (Complete) data for 1-METHYL-2-PYRROLIDINONE (8 total), please visit the HSDB record page.

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Metabolism / Metabolites
The aim was to study the metabolic pathway for N-methyl-2-pyrrolidone in humans. Three healthy male volunteers were administered 100 mg N-methyl-2-pyrrolidone orally. All urine was collected during nine consecutive days. The identification and quantification of the metabolites were performed by gas chromatography/mass spectrometry (GC/MS). N-Methyl-2-pyrrolidone, 5-hydroxy-N-methyl-2-pyrrolidone (5-hydroxy-N-methyl-2-pyrrolidone), N-methylsuccinimide, and 2-hydroxy-N-methylsuccinimide were found in urine. The mean excreted fractions for N-methyl-2-pyrrolidone, 5-hydroxy-N-methyl-2-pyrrolidone, N-methylsuccinimide, and 2-hydroxy-N-methylsuccinimide were 0.8%, 44%, 0.4%, and 20%, respectively. There was no conjugation with glucoronic acid or sulfate or either 5-hydroxy-N-methyl-2-pyrrolidone or 2-hydroxy-N-methylsuccinimide. One-third of the orally dosed N-methyl-2-pyrrolidone was not recovered in urine as either N-methyl-2-pyrrolidone, 5-hydroxy-N-methyl-2-pyrrolidone, N-methylsuccinimide, or 2-hydroxy-N-methylsuccinimide. The half-lives for 5-hydroxy-N-methyl-2-pyrrolidone, N-methylsuccinimide, and 2-hydroxy-N-methylsuccinimide in urine were approximately 4, 8, and 17 hr, respectively.
A method for determination of N-methylsuccinimide and 2-hydroxy-N-methylsuccinimide in human urine and of N-methylsuccinimide in human plasma was developed. N-Methylsuccinimide and 2-hydroxy-N-methylsuccinimide are metabolites of the ... organic solvent N-methyl-2-pyrrolidone. ... The method is applicable for analysis of urine and plasma samples from workers exposed to N-methyl-2-pyrrolidone.
This study described the isolation and identification of the major urinary metabolite of N-methylpyrrolidinone in the male Sprague-Dawley-rat following intravenous administration. The rats were injected via the tail vein with either unlabeled N-methylpyrrolidinone or (14)C labeled N-methylpyrrolidinone at 45 mg/kg. Urine was collected during 0 to 12, 12 to 24, and 24 to 48 hours after dosing and analyzed by gas chromatography/mass spectrometry. Thermospray liquid chromatography/mass spectrometry was performed on samples purified using high performance liquid chromatography method. The major metabolite correlated with 5-hydroxy-N-methylpyrrolidinone based on thin layer chromatography and mass spectral comparisons with an authentic sample.
1-Methyl-2-pyrrolidone is rapidly biotransformed by hydroxylation to 5-hydroxy- N -methyl-2-pyrrolidone, which is further oxidized to N -methylsuccinimide; this intermediate is further hydroxylated to 2-hydroxy- N - methylsuccinimide. These metabolites are all colourless. The excreted amounts of NMP metabolites in the urine after inhalation or oral intake represented about 100% and 65% of the administered doses, respectively.

Toxicity Data
LCLo (rat) = 1,000 mg/m3

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Interactions
The ability of N-methylpyrrolidone and polar lipids to increase the percutaneous delivery of metronidazole was investigated across full thickness human nonoccluded skin in vitro. Fatty acids and ethyl alcohol were also tested and were effected in penetration enhancement in propylene glycol vehicles; N-methylpyrrolidone increased metronidazole penetration from isopropyl myristate vehicles but not from propylene glycol. N-methylpyrrolidone premeated skin readily when applied in the neat state or in a mixture with isopropyl myristate. Results indicated that variations in barrier permeability to metronidazole were associated with the rate of N-methylpyrrolidone permeating the skin.
The effect of a penetration enhancer, N-methylpyrrolidone (N-methyl-2-pyrrolidone) or isopropyl myristate, on the in vitro permeability of gonadorelin (luteinizing hormone-releasing hormone; LHRH) through porcine epidermis was investigated. The permeability coefficient of gonadorelin significantly increased through penetration enhancer treated epidermis in comparison to the control. It was concluded that both penetration enhancers can enhance the percutaneous absorption of peptides such as gonadorelin.
Laurocapram (Azone; 1-dodecylazacycloheptan-2-one; I), N-methylpyrrolidone (N-methyl-2-pyrrolidone; II) and dodecyl-L-pyroglutamate (III) were studied in permeation cells in vitro, for their ability to improve the absorption of insulin (IV) and FD&C Blue No. 1 (brilliant blue FCF; V) through skin; the compounds were formulated into a 40% solution of propylene glycol in increasing concentrations. ... The permeation of V was improved in the presence of II, with concentrations of II ranging from 6.0 to 20.0% exhibiting the same efficacy. In experiments with IV, the optimum efficacy of II was found at a concentration close to 10.0%, with a decline in efficacy in higher and lower concentrations. ...

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Non-Human Toxicity Values
LD50 Rat oral 3914 mg/kg
LD50 Rat oral 4.2 ml/kg
LD50 Mouse oral 7725 mg/kg
LD50 Rabbit dermal 8000 mg/kg
For more Non-Human Toxicity Values (Complete) data for 1-METHYL-2-PYRROLIDINONE (13 total), please visit the HSDB record page.

[1]. Nitrate stimulation of N-Methylpyrrolidone biodegradation by Paracoccus pantotrophus: Metabolite mechanism and Genomic characterization. Bioresour Technol. 2019 Dec;294:122185.

[2]. Novel Metabolic Pathway for N-Methylpyrrolidone Degradation in Alicycliphilus sp. Strain BQ1. Appl Environ Microbiol. 2017 Dec 15;84(1):e02136-17.

N-Methylpyrrolidone can cause developmental toxicity according to The Environmental Protection Agency (EPA).
N-methyl-2-pyrrolidone appears as a clear colorless liquid with a "fishlike" odor. Denser than water. Flash point 199 °F. Contact may irritate skin, eyes and mucous membranes. May be toxic by ingestion.
N-methylpyrrolidin-2-one is a member of the class of pyrrolidine-2-ones that is pyrrolidin-2-one in which the hydrogen attached to the nitrogen is replaced by a methyl group. It has a role as a polar aprotic solvent. It is a N-alkylpyrrolidine, a lactam and a member of pyrrolidin-2-ones.
N Methyl Pyrrolidone is under investigation for the treatment of Multiple Myeloma.
1-Methyl-2-pyrrolidinone has been reported in Microtropis japonica, Melicope hayesii, and other organisms with data available.
1-Methyl-2-pyrrolidone, or N-Methyl-2-pyrrolidone (NMP), is a chemical compound with 5-membered lactam structure. It is a colorless to slightly yellow liquid miscible with water. It is used in petrochemical processing, and as a solvent for surface treatment of textiles, resins and metal coated plastics or as a paint stripper. In the pharmaceutical industry, N-methyl-2-pyrrolidone is used in the formulation for drugs by both oral and transdermal delivery routes. NMP has been identified as a reproductive toxicant, first by California in 2001[3] and then by the European Commission in 2003. In the face of increasing regulation, some manufacturers are considering alternative solvents for some applications, especially where worker exposure is difficult to control, such as in paint stripping, graffiti removal, and agriculture. (Wikipedia)

C5H9NO

99.13

99.068

872-50-4

N-Methyl-2-pyrrolidone-d3;933-86-8

13387

Colorless to light yellow liquid

1.0±0.1 g/cm3

202.0±0.0 °C at 760 mmHg

−24 °C(lit.)

86.1±0.0 °C

0.3±0.4 mmHg at 25°C

1.470

-0.4

0

1

0

7

90.1

0

O=C1CCCN1C

SECXISVLQFMRJM-UHFFFAOYSA-N

InChI=1S/C5H9NO/c1-6-4-2-3-5(6)7/h2-4H2,1H3

1-methylpyrrolidin-2-one

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)

DMSO: 100 mg/mL (1008.78 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.)