The LD50 of paraquat in different animals [2] is determined by the number of animals in each group, their body weight (g), and the route of administration (mg/kg). Female rats 6 130-160 Oral 112 (104-122) Female rats 10 150-205 Oral 150 (139-162) Female rats 6 130-160 Intraperitoneal 19 (16-21) Female rat 6 130-160 Intraperitoneal 16 (14-19) Female guinea pig 3 400 -500 intraperitoneal injection 3 Male guinea pig 5 190-250 oral 262 (200-346) Female cat 3 2500-4400 oral 35 (27 –46)

Metabolism / Metabolites
Paraquat is poorly absorbed after oral exposure. It is not metabolized but is reduced to an unstable free radical which is then re-oxidized to reform the cation and produce a superoxide anion. It is excreted moslty in the urine,and in small fraction also in the feces (A606, L1008).

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Biological Half-Life
Animal studies: less than 6 hours; other animal studies have found measurable paraquat 26 days after ingestion; [TDR, p. 991]

Toxicity Summary
The mechanisms of the toxic effects of paraquat are largely the result of a metabolically catalyzed single electron oxidation reduction reaction, resulting in depletion of cellular NADPH and the generation of potentially toxic forms of oxygen such as the superoxide radical (A607). Recent studies have demonstrated paraquat cytotoxicity occurs in the mitochondria and particularly in mitochondrial-rich tissues. The mitochondrial NADH-dependent PQ reductase containing a voltage-dependent anion channel 1 (VDAC1) appears to be largely responsible for paraquat cytotoxicity. When mitochondria are incubated with NADH and paraquat, the superoxide anion is produced, and the mitochondria rupture. Ruptured mitochondria lead to rapid cell death (A3102).

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Toxicity Data
LCLo (rat) = 1 mg/m3/6H for respirable dust;
LD50: 150 mg/kg (Oral, Rat) (L1008)
LD50: >480 mg/kg (Dermal, Rabbit) (L1008)

[1]. Hamadi NK, et al. Adsorption of Paraquat dichloride from aqueous solution by activated carbon derived from used tires. J Hazard Mater. 2004 Aug 9;112(1-2):133-41.
[2]. Clark D G, et al. The toxicity of paraquat[J]. Occupational and Environmental Medicine, 1966, 23(2): 126-132.
[3]. Ladipo M K, et al. Acute Toxicity, Behavioural Changes and Histopathological Effect of Paraquat Dichloride on Tissues of Catfish (Clarias Gariepinus)[J]. International Journal of Biology, 2011.
[4]. Lock E A, et al. Paraquat[M]//Hayes' Handbook of Pesticide Toxicology. Academic Press, 2010: 1771-1827.

Paraquat dichloride is a colorless to yellow crystalline solid. Used as a contact herbicide and desiccant. (EPA, 1998)
Paraquat dichloride is an organic chloride salt. It has a role as a herbicide and a photosystem-I inhibitor. It contains a paraquat.
Paraquat dichloride is a constituent of numerous proprietary herbicides. A large majority (93%) of fatalities from paraquat poisoning are cases of intentional self-administration, ie, suicides. In third world countries, paraquat is a major suicide agent. For instance, in Samoa from 1979-2001, 70% of suicides were by Paraquat poisoning. In Southern Trinidad from 1996-1997, 76% of suicides were by paraquat. However, independent bodies have studied paraquat in this use. Jenny Pronczuk de Garbino, stated: no lung or other injury in marijuana users has ever been attributed to paraquat contamination. Also a United States Environmental Protection Agency manual states: … toxic effects caused by this mechanism have been either very rare or nonexistent. Most paraquat that contaminates marijuana is pyrolyzed during smoking to dipyridyl, which is a product of combustion of the leaf material itself (including marijuana) and presents little toxic hazard. Paraquat is the trade name for N,N -dimethyl-4,4 -bipyridinium dichloride, one of the most widely used herbicides in the world. Paraquat, a viologen, is quick-acting and non-selective, killing green plant tissue on contact. It is also toxic to human beings when swallowed. Paraquat is used as a quaternary ammonium herbicide; one of the most widely used herbicides in the world. It is quick-acting, non-selective, and kills green plant tissue on contact. It is redistributed within the plant but does not harm mature bark. Being a herbicide, paraquat protects crops by controlling a wide range of annual and certain perennial weeds that reduce crop yield and quality by competing with the crop for water, nutrients, and light. Pure paraquat ingested is highly toxic to mammals and humans potentially leading to acute respiratory distress syndrome (ARDS), and there are no specific antidotes. However, fuller's earth or activated charcoal is an effective treatment, if taken in time. Death may occur up to 30 days after ingestion. Diluted paraquat used for spraying is less so, thus the greatest risk of accidental poisoning is during mixing and loading Paraquat for use.
A poisonous dipyridilium compound used as contact herbicide. Contact with concentrated solutions causes irritation of the skin, cracking and shedding of the nails, and delayed healing of cuts and wounds.
See also: Paraquat (annotation moved to).

C12H14CL2N2

257.16

256.053

1910-42-5

1910-42-5 (chloride);1983-60-4 (iodide);4685-14-7 (cation);75365-73-0 (Chloride hydrate);

15938

Typically exists as solid at room temperature

1.25

175ºC

>300 °C(lit.)

0

2

1

16

145

0

C[N+]1=CC=C(C=C1)C2=CC=[N+](C)C=C2.[Cl-].[Cl-]

FIKAKWIAUPDISJ-UHFFFAOYSA-L

InChI=1S/C12H14N2.2ClH/c1-13-7-3-11(4-8-13)12-5-9-14(2)10-6-12;;/h3-10H,1-2H3;2*1H/q+2;;/p-2

1-methyl-4-(1-methylpyridin-1-ium-4-yl)pyridin-1-ium;dichloride

Paraquat dichloride NSC-263500 NSC 263500

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)

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.)