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
Oral absorption of paraquat is low. It is not metabolized but reduced to unstable free radicals, which are then re-oxidized to form cations and produce superoxide anions. It is primarily excreted in urine, with small amounts also excreted in feces (A606, L1008). Biological Half-Life Animal studies: less than 6 hours; other animal studies have found paraquat detectable up to 26 days after ingestion; [TDR, page 991]

Toxicity Summary
The toxic mechanism of paraquat primarily stems from metabolically catalyzed single-electron redox reactions, leading to intracellular NADPH depletion and the generation of potentially toxic oxygen free radicals (such as superoxide anion radicals (A6O7)). Recent studies have shown that paraquat cytotoxicity mainly occurs in mitochondria, particularly in mitochondria-rich tissues. NADH-dependent paraquat reductase, containing voltage-dependent anion channel 1 (VDAC1) in mitochondria, appears to be the primary cause of paraquat cytotoxicity. When mitochondria are incubated with NADH and paraquat, superoxide anions are generated, leading to mitochondrial rupture. Mitochondrial rupture results in rapid cell death (A3102). Toxicity Data
LCLo (rat) of inhalable dust = 1 mg/m3/6H; LD50: 150 mg/kg (oral, rat) (L1008); LD50: >480 mg/kg (skin, 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 organochloride salt with herbicidal and photosystem I inhibitor properties; its main component is paraquat. Paraquat dichloride is one of the ingredients in many commercial herbicides. The vast majority (93%) of paraquat poisoning deaths are intentional suicides. In developing countries, paraquat is a leading suicide drug. For example, between 1979 and 2001, 70% of suicides in Samoa were due to paraquat poisoning; between 1996 and 1997, 76% of suicides in southern Trinidad were due to paraquat poisoning. However, some independent institutions have also studied this use of paraquat. Jenny Pronczuk de Garbino noted that there have never been any cases of cannabis users suffering lung or other damage due to paraquat contamination. A manual from the U.S. Environmental Protection Agency also states: "...the toxicity caused by this mechanism is very rare or non-existent." Most paraquat contaminating cannabis decomposes into dipyridine during ingestion, a product of the combustion of cannabis leaves themselves, and has very low toxicity. Paraquat is the trade name for N,N-dimethyl-4,4'-bipyridine dichloride, one of the most widely used herbicides in the world. Paraquat is a violaride herbicide, fast-acting and non-selective, killing green plant tissue upon contact. Ingestion of paraquat is also toxic to humans. Paraquat is a quaternary ammonium salt herbicide, also one of the most widely used herbicides in the world. It acts rapidly and non-selectively, killing green plant tissue upon contact. It redistributes within the plant but does not damage mature bark. As a herbicide, paraquat protects crops by controlling a variety of annual and some perennial weeds that compete with crops for water, nutrients, and sunlight, thus reducing crop yield and quality. Ingestion of pure paraquat is highly toxic to mammals and humans, potentially causing acute respiratory distress syndrome (ARDS), for which there is currently no specific antidote. However, bleaching soil or activated charcoal are effective treatments if ingested promptly. Death can occur within 30 days of ingestion. Diluted paraquat used for spraying is less toxic; therefore, the greatest risk of accidental poisoning occurs during the mixing and loading of paraquat. Paraquat is a toxic dipyridine compound used as a contact herbicide. Contact with concentrated solutions can cause skin irritation, nail splitting and shedding, and delayed wound healing. See also: Paraquat (note 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.)