β-tubulin (no IC50, Ki, EC50, or DC50 values provided in this study).[1]
Flubendazole targets the microtubules of parasitic worms. Like other benzimidazoles, it binds to β-tubulin, inhibiting its polymerization into microtubules. This disrupts the formation of the mitotic spindle, leading to cell division arrest and the death of the parasite. Flubendazole has a high affinity for parasite β-tubulin, which contributes to its selective toxicity. In cancer research, it is studied for its ability to target microtubules in cancer cells, although its primary use remains as an anthelmintic.

Flubendazole results in morphological changes included contraction of the soma region, formation of blebs on the tegument, rostellar disorganization, loss of hooks and destruction of microtriches in Echinococcus granulosus. Flubendazole have a bicyclic ring system in which a benzene has been fused to the -4 and -5 positions of the heterocycle (imidazole). Flubendazole and Albendazole shows similar potency in affecting rat embryonic development in vitro, inducing retardation of growth and dysmorphogenic effects at concentrations ≥0.5 μg/mL.

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Flubendazole at concentrations of 10, 5 and 1 μg/ml provoked a protoscolicidal effect against Echinococcus granulosus protoscoleces in vitro, reducing vitality to 35.6±0.7% after 18 days of incubation. After 25 days of incubation, the percentage of vital protoscoleces was 13.9±5.9%. After 30 days, mortality was 100% at concentrations of 10 and 1 μg/ml, and only 0.7±0.7% vital protoscoleces were observed at 5 μg/ml. The primary site of damage was the tegument of the parasite. At 3 days post-incubation (p.i.), numerous blebs on the tegument were observed. At 6 days p.i., soma region contraction and numerous blebs on the scolex tegument were seen; microtriches remained unaltered. At 12 days p.i., rostellar disorganization, loss of hooks, shedding of microtriches, and digitiform tegumental extensions on the soma region were observed; large vacuoles appeared in the distal cytoplasm. At 18 days p.i., loss of morphology, loss of hooks, altered sucker region with blebs, and no detectable microtriches were evident; soma region contracted with markedly altered tegument. At 25 days p.i., complete loss of morphology, rostellar disorganization, complete shedding of microtriches, severely affected internal tissue with increased lipid droplets, and vitality approximately 13.9±5.9%. Flubendazole killed protoscoleces considerably faster than albendazole (ABZ) or albendazole sulphoxide (ABZSO); after 25 days exposure to Flubendazole, vitality was ~13.9±5.9% compared to 50% after 24 days with ABZ or ABZSO.[1]
Time of appearance of tissue damage indicators: contraction of soma region at 6 days p.i.; formation of blebs on tegument at 6 days p.i.; rostellar disorganization at 12 days p.i.; complete shedding of microtriches at 18 days p.i.[1]
In vitro, Flubendazole has been shown to be a potent inhibitor of parasite growth and development. It effectively kills a wide range of nematodes and other helminths in culture. Studies have also demonstrated its activity against various cancer cell lines, where it induces cell cycle arrest and apoptosis by disrupting microtubules. Its in vitro activity against parasites is well-characterized, and it is used as a reference compound in anthelmintic screening assays.

Flubendazole (6.32 mg/kg/day) initially induces an arrest of embryonic development followed by a generalized cell death that leads to 100% embryolethality by gestation day (GD) 12.5. Flubendazole (3.46 mg/kg/day) markedly reduces embryonic development by GD 12.5 without causing cell death. Flubendazole in olive oil causes a statistically significant increase in embryolethality at doses of 7.83 mg/kg per day and higher, with complete resorption in all dams at 31.33 mg/kg per day in rats. Flubendazole treatment causes a slight increase of metyrapone and daunorubicin activities in hepatic as well as intestinal cytosol in birds. Flubendazole treatment leads to statistically significant inhibition of intestinal GST activity. Flubendazole treatment leads to slight but significant inhibition (decrease to 69%) of 7-ethoxyresorufin activity in hepatic microsomes.
In vivo, Flubendazole is an orally active anthelmintic used in veterinary medicine. It is effective against a broad spectrum of parasitic worms in various animal species. It is administered as a feed additive or as a drench to treat and control worm infestations. Its efficacy has been demonstrated in numerous field studies. In research settings, it has also been studied in animal models of cancer, where it has shown some antitumor activity.

Non-cellular assays for Flubendazole typically involve measuring its ability to inhibit tubulin polymerization. These assays use purified tubulin and measure the rate of microtubule formation in the presence of the compound. The inhibition of tubulin polymerization is a key parameter for characterizing its mechanism of action. These experiments are essential for understanding its interaction with its molecular target.

Protoscoleces of Echinococcus granulosus were collected aseptically from liver and lung hydatid cysts of infected cattle. Viability was assessed by muscular movements (evaluated under light microscope), morphological perfectness of the whole body determined using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), motility of flame cells, and by the methylene blue exclusion test. Viable and free protoscoleces (1,500 per Leighton tube) were cultured in medium 199 spiked with 100 IU penicillin, 100 μg/ml streptomycin and 4 mg/ml glucose. Cultures were performed in 10 ml of incubation medium at 37°C without changes of medium. Flubendazole was dissolved in dimethyl sulphoxide (DMSO) at a drug concentration of 10 mg/ml and added to the medium resulting in final concentrations of 10, 5 and 1 μg/ml. Protoscoleces incubated with culture medium alone and with culture medium containing DMSO were used as controls. Culture tubes were followed microscopically every day. Samples of protoscoleces (approximately 70-90 protoscoleces in 0.5 ml of incubation medium) from each dosing group and controls were taken every 5-6 days for up to 46 (control group) or 35 (Flubendazole group) days. Vitality of protoscoleces was assessed using the methylene blue exclusion technique. Additionally, ultrastructure studies with SEM and TEM were performed. For SEM, samples were fixed with 3% glutaraldehyde in sodium cacodylate buffer for 24 h at 4°C, washed in cacodylate buffer, dehydrated in increasing concentrations of ethanol (50-100%), immersed in hexamethyldisilazane for 5 min, 1 h and then overnight, sputter-coated with gold (100 Å thick), and inspected on a scanning electron microscope operating at 15 kV. For TEM, samples were post-fixed in 2% OsO4 in cacodylate buffer, washed in water, dehydrated in a graded acetone series, embedded in Spurr's resin, polymerized at 70°C overnight, sections 700 Å thick were cut, stained with uranyl acetate saturated solution (45 min) and lead citrate (20 min), and examined with a transmission electron microscope at 80 kV.[1]
In vitro cell-based assays for Flubendazole are used to study its effects on parasites and cancer cells. For parasites, these assays involve culturing worms or parasite larvae in the presence of the compound and assessing their viability and development. For cancer research, assays using cancer cell lines measure cell proliferation, cell cycle distribution, and apoptosis. These studies help to confirm its mechanism of action and to explore its potential therapeutic applications.

6.32, 7.83, 31.33 mg/kg/day Birds
In vivo animal studies for Flubendazole are standard for evaluating its anthelmintic efficacy. The compound is typically administered orally to animals infected with parasitic worms. The reduction in worm burden is assessed at the end of the study. These studies are crucial for validating its efficacy as an anthelmintic. In cancer research, animal models of cancer are used to study its antitumor activity.

Flubendazole is an orally active anthelmintic. It has a molecular weight of 313.28 g/mol. After oral administration, it is absorbed from the gastrointestinal tract and distributed to tissues. It is metabolized in the liver and excreted primarily in the feces. Its pharmacokinetic profile in animals is well-characterized, supporting its use as a veterinary drug.

Flubendazole has an established safety profile from its use in veterinary medicine. It is generally well-tolerated in animals at therapeutic doses. However, as with all drugs, it can have side effects. Comprehensive toxicological data are available from its veterinary use. Flubendazole is not approved for human use and is primarily a veterinary drug and research compound.

Parasitol Res.2006 Mar;98(4):317-23.

Flubendazole belongs to the mebendazole class of drugs, with its benzoyl group replaced by a p-fluorobenzoyl group. It is a broad-spectrum anthelmintic, particularly used in veterinary medicine to treat nematode infections. It is both an anti-nematode and a teratogen. It belongs to the benzimidazole, carbamate, organofluorine, and aromatic ketone classes of compounds. Flubendazole is an anthelmintic used to treat human helminth infections. In Europe, it is available without a prescription.

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Flubendazole (FLBZ) is a benzimidazole methylcarbamate anthelmintic. Benzimidazole anthelmintics exert their action by binding to β-tubulin, thereby inhibiting the polymerization of microtubules, which induces blockage of glucose absorption, glycogen depletion, degenerative alterations in the endoplasmic reticulum and mitochondria of the germinal layer, and an increase in lysosomes with consequent cellular autolysis. Mebendazole (MBZ) and albendazole (ABZ) have been used for treatment of human hydatid disease. Flubendazole has been used to treat cystic echinococcosis in humans but low in vivo efficacy has been reported. This work describes for the first time the protoscolicidal effect of Flubendazole in vitro on cultured Echinococcus granulosus. The authors concluded that further in vitro (at lower concentrations) and in vivo experiments are required to fully evaluate the potential of Flubendazole as a useful anthelmintic for treatment of CE.[1]
Flubendazole (Flutelmium) is a broad-spectrum benzimidazole anthelmintic used in veterinary medicine. It targets β-tubulin, disrupting microtubule formation and leading to parasite death. It is effective against a wide range of gastrointestinal nematodes, lungworms, and tapeworms. Flubendazole is also studied in cancer research for its potential antitumor properties. It is not approved for human use.

C16H12FN3O3

313.28

313.086

31430-15-6

Flubendazole-d3;1173021-08-3

35802

White to off-white solid powder

1.4±0.1 g/cm3

290°C

1.685

3.05

2

5

4

23

454

0

O=C(OC)NC1=NC2=CC=C(C(C3=CC=C(F)C=C3)=O)C=C2N1

CPEUVMUXAHMANV-UHFFFAOYSA-N

InChI=1S/C16H12FN3O3/c1-23-16(22)20-15-18-12-7-4-10(8-13(12)19-15)14(21)9-2-5-11(17)6-3-9/h2-8H,1H3,(H2,18,19,20,22)

methyl (5-(4-fluorobenzoyl)-1H-benzo[d]imidazol-2-yl)carbamate

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)

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.)