Fenbendazole dry suspension and preparation method thereof

Abstract

The invention discloses a fenbendazole dry suspension and a preparation method thereof, and belongs to the field of veterinary drug preparations, and the fenbendazole dry suspension provided by the invention is prepared from the following components in parts by weight: 3-10 parts of fenbendazole, 2-10 parts of a suspending aid, 2-10 parts of a nonionic surfactant, 3-5 parts of a dispersant, 70-90 parts of a carrier, 3-10 parts of a solvent and 0.01-2 parts of an antioxidant. The fenbendazole disclosed by the invention is good in suspension property, not easy to settle and good in stability in water. The fenbendazole dry suspension is simple in preparation method, good in stability, convenient to transport, high in bioavailability and wide in market prospect.

Description

Technical Field

[0001] The present invention belongs to the field of veterinary drug preparations, and particularly relates to a fenbendazole dry suspension and a preparation method thereof. Background Art

[0002] Fenbendazole is a broad-spectrum, highly effective, and low-toxic benzimidazole anti-parasitic drug. It has two mechanisms of action. One is that it can inhibit fumarate reductase in parasites to expel worms; the other theory is that it inhibits the electron transport system in the mitochondria of worms and the phosphorylation reaction coupled with the electron transport body, inhibits the glucose transport system related to microtubule formation, and then blocks the synthesis of ATP. Fenbendazole has good effects on gastrointestinal nematodes, Dictyocaulus filaria, Fasciola, and tapeworms, and also has a very strong effect on killing eggs. Its anti-parasitic effect is stronger than that of albendazole. It is widely used to expel internal parasites in sheep, cattle, horses, pigs, poultry, dogs, cats, and wild animals, etc. It has a long-lasting drug effect and small toxic and side effects. Fenbendazole is an anti-parasitic drug approved for the production of green food in China and is also a commonly used anti-parasitic drug in developed European countries.

[0003] Since fenbendazole is poorly soluble in water, the commonly used preparations in veterinary clinics mainly include tablets, powders, granules, suspensions, nanoemulsions, etc. During the application process, there are often situations where the tablets are spat out, resulting in insufficient actual dosage, and it is time-consuming and laborious to administer, and the operation and use are inconvenient. Fenbendazole suspension and fenbendazole emulsion are liquid preparations with poor stability and relatively high transportation costs; the bioavailability of fenbendazole nano-suspension preparation is relatively high, but it requires expensive production equipment, and both the production cost and transportation cost are relatively high. There are various preparation methods for fenbendazole powder, the production process is simple, it can be industrially produced, which is conducive to mass medication and reduces the medication cost. However, conventional fenbendazole powders are all administered by mixing with feed, and there are problems such as poor gastrointestinal absorption, low bioavailability, and inconvenient use. How to prepare fenbendazole powder with low cost, good stability, high bioavailability, and can be administered by drinking water has always been a research hotspot in the field of veterinary pharmaceuticals. The fenbendazole powder preparations that can be administered by drinking water published in existing patents include fenbendazole dry suspension preparations, fenbendazole dry emulsions, water-soluble fenbendazole powders, etc. Among them, in Patent CN116602964A, fenbendazole is emulsified with polyethylene glycol and then spray-dried to obtain fenbendazole powder. Although this product can dissolve in water, it is prone to sedimentation and clog the water pipe, and is suitable for use by mixing with feed. In Patents CN105456199A, CN105456260B, and CN103340884B, the surfactants used are ionic surfactants such as sodium dodecyl sulfate, sodium octadecyl sulfate, and sodium hexadecyl sulfate. Such surfactants can dissolve fenbendazole in water, but the emulsification state of the drug in water is poor and the precipitation is relatively fast. Patent CN 115429761A is a fenbendazole nanocrystal solid dispersion, prepared by grinding with a media mill, with good stability and relatively high bioavailability, but it has high requirements for production equipment, and there is a large loss during the production process, increasing the production cost. This patent will disclose a preparation method and application of a fenbendazole dry suspension with simple preparation process, low cost, stable quality, convenient drug administration, high efficiency and low toxicity. It has the same drug effect as the solution-type fenbendazole suspension, and its suspension property is better than that of ordinary dry suspensions. It can be administered by drinking water or by mixing with feed, and is used for the prevention and treatment of internal parasites in livestock and poultry. Summary of the Invention

[0004] To solve the above technical problems, the present invention provides a fenbendazole dry suspension, which is prepared from the following components in parts by weight: 3-10 parts of fenbendazole, 2-10 parts of suspending agent, 2-10 parts of non-ionic surfactant, 3-5 parts of dispersant, 70-90 parts of carrier, 3-10 parts of solvent, and 0.01-2 parts of antioxidant.

[0005] Further, the dry suspension is prepared from the following components in parts by weight: 3-5 parts of fenbendazole, 5-10 parts of suspending agent, 2-5 parts of non-ionic surfactant, 3-4 parts of dispersant, 80-90 parts of carrier, 5-10 parts of solvent, and 0.01-1 part of antioxidant.

[0006] Further, the dry suspension is prepared from the following components in parts by weight: 5 parts of fenbendazole, 10 parts of suspending agent, 5 parts of non-ionic surfactant, 3 parts of dispersant, 80 parts of carrier, 10 parts of solvent, and 0.1 part of antioxidant.

[0007] Preferably, the non-ionic surfactant is selected from one or more of the following: Tween-40, Tween-60, Tween-80, Myrj-49, Myrj-51, Myrj-52, polyoxyethylene hydrogenated castor oil 35, polyoxyethylene hydrogenated castor oil 40, polyoxyethylene hydrogenated castor oil 50, hydrogenated castor oil 35, hydrogenated castor oil 40.

[0008] Preferably, the suspending agent is selected from one or more of the following: gum arabic, xanthan gum, sodium alginate, methylcellulose, β-cyclodextrin, hydroxypropyl methylcellulose, sodium carboxymethylcellulose, konjac gum, hydroxypropyl β-cyclodextrin, thickening agent.

[0009] Preferably, the dispersant is selected from one or more of the following: trisodium phosphate, silicon dioxide, polyvinylpyrrolidone, polyethylene glycol 4000, polyethylene glycol 6000.

[0010] Preferably, the carrier is selected from one or more of the following: soluble starch, anhydrous glucose, lactose, maltodextrin.

[0011] Preferably, the solvent is selected from one or more of the following: water, ethanol, ethyl acetate.

[0012] Preferably, the antioxidant is selected from one or more of the following: sodium bisulfite, sodium metabisulfite, anhydrous sodium sulfate, potassium sorbate, gallate, butylated hydroxyanisole, 2,6-di-tert-butyl-4-methylphenol, tert-butylhydroquinone.

[0013] The present invention also provides a preparation method of fenbendazole dry suspension with simple preparation process, low cost, stable quality, convenient dosing, high efficiency and low toxicity to solve the problem of poor suspension of existing fenbendazole powder after being dissolved in water.

[0014] The fenbendazole dry suspension is prepared by the following steps:

[0015] (1) Pretreatment of fenbendazole: After mixing the non-ionic surfactant and the solvent evenly, add the fenbendazole raw material, stir evenly, dry, crush, and pass through a No. 5 sieve for standby;

[0016] (2) Add the processed fenbendazole powder, suspending agent, carrier, dispersant, and antioxidant into a mixer and mix evenly to obtain the fenbendazole dry suspension.

[0017] The beneficial effects of the present invention compared with the prior art are as follows:

[0018] The fenbendazole dry suspension provided by the present invention has undergone stability tests, sedimentation tests, clinical safety evaluations, and efficacy evaluations, etc. The tests show that the fenbendazole dry suspension prepared by the present invention has no obvious sedimentation after being dissolved in water (the content of fenbendazole in water is still above 90% after standing for 4 hours), has good suspension in water, and good stability. Its preparation process is simple, the cost is low, the quality is stable, the drug administration is convenient, it is highly effective and low-toxic, and has a broad market prospect.

[0019] The content of organic solvents in the fenbendazole dry suspension provided by the present invention is small, safe and environmentally friendly, and convenient for transportation: the organic solvents in the fenbendazole dry suspension of the present invention are removed by drying, and the remaining amount is much smaller than the addition amount of organic solvents in the fenbendazole suspension and fenbendazole emulsion, which is safer for animals and convenient for transportation. The fenbendazole dry suspension is added with a non-ionic surfactant to promote the emulsification and intestinal absorption of fenbendazole, and the bioavailability is improved.

[0020] The preparation process of the fenbendazole dry suspension of the present invention is simple and the cost is low. Compared with the fenbendazole nano dry suspension and fenbendazole suspension, the preparation process of the fenbendazole dry mixture of the present invention is simple, does not require complex process equipment, the production cost is low, and it is more suitable for popularization and application. Specific embodiments

[0021] The following examples are used to illustrate the present invention, but do not limit the scope of the present invention.

[0022] Example 1 Preparation of the pharmaceutical composition of the present invention

[0023] Weigh the drug raw materials and excipients according to the weight ratio: 3 g of fenbendazole, 5 g of methylcellulose, 5010 g of polyoxyethylene hydrogenated castor oil, 5 g of polyvinylpyrrolidone K30, 76.9 g of lactose, 5 g of pure water, and 0.1 g of butylated hydroxyanisole.

[0024] Prepare according to the following method:

[0025] (1) Add the prescribed amount of polyoxyethylene hydrogenated castor oil 50 to pure water, stir and dissolve, then add the fenbendazole raw material drug, dry at 50 °C, crush, and pass through a No. 5 sieve.

[0026] (2) Mix the fenbendazole powder, methylcellulose, polyvinylpyrrolidone K30, lactose, and butylated hydroxyanisole processed in the previous step evenly.

[0027] Example 2 Preparation of the Pharmaceutical Composition of the Invention

[0028] Weigh the drug raw materials and excipients according to the weight ratio: 10 g of fenbendazole, 10 g of sodium carboxymethylcellulose, 5 g of Tween 80, 3 g of trisodium phosphate, 71.9 g of soluble starch, 5 g of ethanol, and 0.1 g of sodium metabisulfite.

[0029] Prepare according to the following method:

[0030] (1) Stir and mix the prescribed amount of Tween 80 and ethanol evenly, add the fenbendazole raw material drug and stir evenly, dry at 50 °C, pulverize, and pass through a No. 5 sieve.

[0031] (2) Mix the processed fenbendazole powder, sodium carboxymethylcellulose, trisodium phosphate, soluble starch, and sodium metabisulfite evenly.

[0032] Example 3 Preparation of the Pharmaceutical Composition of the Invention

[0033] Weigh the drug raw materials and excipients according to the weight ratio: 5 g of fenbendazole, 10 g of β-cyclodextrin, 2 g of Myrj-51, 3 g of silicon dioxide, 79.9 g of maltodextrin, 10 g of ethyl acetate, and 0.1 g of 2,6-di-tert-butyl-4-methylphenol.

[0034] Prepare according to the following method:

[0035] (1) Mix the prescribed amount of Myrj-51 and ethyl acetate evenly, add the fenbendazole raw material drug and stir evenly, dry at 50 °C, pulverize, and pass through a No. 5 sieve.

[0036] (2) Mix the processed fenbendazole powder, β-cyclodextrin, silicon dioxide, maltodextrin, and 2,6-di-tert-butyl-4-methylphenol evenly.

[0037] Example 4 Preparation of the Pharmaceutical Composition of the Invention

[0038] Weigh the drug raw materials and excipients according to the weight ratio: 3 g of fenbendazole powder, 2 g of arabic gum, 355 g of polyoxyethylene hydrogenated castor oil, 3 g of polyvinylpyrrolidone K30, 86.9 g of anhydrous glucose, 3 g of ethyl acetate, and 0.1 g of gallate.

[0039] Prepare according to the following method:

[0040] (1) Mix the prescribed amount of polyoxyethylene hydrogenated castor oil 35 and ethyl acetate evenly, add the fenbendazole raw material drug and stir evenly, dry at 50 °C, pulverize, and pass through a No. 5 sieve.

[0041] (2) Mix the processed fenbendazole powder, arabic gum, polyvinylpyrrolidone K30, anhydrous glucose, and gallate evenly.

[0042] Example 5 Preparation of the Pharmaceutical Composition of the Present Invention

[0043] Weigh the drug raw and auxiliary materials according to the weight ratio: 5 g of fenbendazole powder, 2 g of xanthan gum, 35.5 g of hydrogenated castor oil, 3 g of polyethylene glycol 4000, 84.9 g of soluble starch, 3 g of ethanol, and 0.1 g of butylated hydroxyanisole.

[0044] Prepare according to the following method:

[0045] (1) Mix the prescribed amount of 35 of hydrogenated castor oil and ethanol evenly, add the fenbendazole raw material and stir evenly, dry at 50 °C, pulverize, and pass through a No. 5 sieve.

[0046] (2) Mix the treated fenbendazole powder, xanthan gum, polyethylene glycol 4000, soluble starch, and butylated hydroxyanisole evenly.

[0047] Example 6 Preparation of the Pharmaceutical Composition of the Present Invention

[0048] Weigh the drug raw and auxiliary materials according to the weight ratio: 5 g of fenbendazole powder, 5 g of sodium alginate, 5 g of Tween 60, 3 g of silicon dioxide, 81.9 g of lactose, 3 g of pure water, and 0.1 g of sodium bisulfite.

[0049] Prepare according to the following method:

[0050] (1) Mix the prescribed amount of Tween 60 and pure water evenly, add the fenbendazole raw material and stir evenly, dry at 50 °C, pulverize, and pass through a No. 5 sieve.

[0051] (2) Mix the treated fenbendazole powder, sodium alginate, silicon dioxide, lactose, and sodium bisulfite evenly.

[0052] Comparative Example 1

[0053] Weigh the drug raw and auxiliary materials according to the weight ratio: 10 g of fenbendazole, 10 g of sodium carboxymethylcellulose, 5 g of Tween 80, 3 g of trisodium phosphate, 74.9 g of soluble starch, 5 g of ethanol, 0.1 g of sodium metabisulfite, and an appropriate amount of pure water.

[0054] Prepare according to the following method:

[0055] (1) Mix the prescribed amount of fenbendazole, sodium carboxymethylcellulose, trisodium phosphate, soluble starch, and sodium pyrophosphate evenly to obtain mixture A.

[0056] (2) Mix Tween 80, ethanol, and pure water evenly, add them to mixture A, granulate by wet method, dry, and pulverize to obtain fenbendazole powder that can be dissolved in water.

[0057] Comparative Example 2

[0058] Weigh the drug raw materials and excipients according to the weight ratio: 5 g of fenbendazole, 25 g of poloxamer 188, 0.15 g of sodium lauryl sulfate, 20.25 g of sorbitol, 10 g of PEG-6000, 0.5 g of dimethyl silicone oil, and 15 mL of distilled water.

[0059] The preparation is carried out as follows: First, dissolve poloxamer 188 and sodium lauryl sulfate in water, then add dimethyl silicone oil and stir evenly. Next, add fenbendazole, poloxamer, and PEG6000 to a trough mixer and stir until it becomes granular. Take it out, dry it, and crush it until it completely passes through a No. 9 sieve.

[0060] Comparative Example 3

[0061] Weigh the drug raw materials and excipients according to the weight ratio: Take 4 g of fenbendazole, 85 g of powdered sugar, 7 g of sodium lauryl sulfate, and 4 g of xanthan gum.

[0062] The preparation is carried out as follows:

[0063] (1) Dissolve sodium lauryl sulfate in 5 g of water, add the fenbendazole raw material and stir evenly, then dry, crush, and pass through a No. 5 sieve.

[0064] (2) Add the fenbendazole powder obtained in (1), xanthan gum, and powdered sugar and mix evenly.

[0065] The beneficial effects of the present invention are further illustrated by the following experiments:

[0066] Test Example 1 Stability Test

[0067] 1 Materials and Methods: Take the samples of Test Examples 1-6 and conduct high-temperature tests and accelerated tests according to the guiding principles for the stability study of veterinary chemical drugs in the "Compilation of Guiding Principles for Veterinary Drug Research and Technology 2006-2011".

[0068] High-temperature test: Take the samples of Examples 1-6 and place them at 60 °C for 10 days. On the 0th day, 5th day, and 10th day, detect the changes in the drug content of fenbendazole and the physical properties. Accelerated test: Take the samples of Examples 1-6, in the commercial package, and conduct a 6-month test under the conditions of 40 ± 2 °C and RH (75 ± 5)%. Samples are taken at the end of the 0th, 1st, 2nd, 3rd, 4th, 5th, and 6th months during the test to detect the content and physical property changes of fenbendazole.

[0069] 2 Test results: The results of the high-temperature test and the accelerated test are shown in Table 1 and Table 2. The results of the high-temperature test indicate that the samples of Examples 1-6 showed no obvious changes in their properties and contents after being placed at 60 °C for 10 days, meeting the requirements of the stability guiding principles. The results of the accelerated test show that the samples of Test Examples 1-6 were stable in terms of content and properties after being placed at 40 ± 2 °C and RH (75 ± 5)% for 6 months. This shows that the stability of the febantel dry suspension of this invention patent meets

[0070] the provisions of the Chinese Veterinary Pharmacopoeia.

[0071] Table 1. Results of the high-temperature stability test

[0072]

[0073]

[0074] Table 2. Results of the accelerated stability test

[0075]

[0076]

[0077] Test Example 2 Sedimentation test

[0078] We optimized the sedimentation detection method for the febantel dry suspension, and used high-performance liquid chromatography to detect the content of febantel in water after the febantel dry suspension was dissolved in water. The sedimentation of Examples 1-6 and Comparative Examples 1-3 was compared, and the specific method is as follows:

[0079] 1 Materials and methods:

[0080] Take 1 g of the samples of Examples 1-6 and Comparative Examples 1-3 respectively in 1000 mL of water. There are 4 parallels for each sample. After stirring evenly, start timing (the number of stirring times for each parallel is the same). The first sample (sampling at 0 h), the second sample (sampling at 1 h), the third sample (sampling at 2 h), and the fourth sample (sampling at 4 h). Samples are taken from the middle of the upper layer and the middle of the lower layer for each sample. Each time, 10 mL is taken and placed in a 100 mL volumetric flask. Add 80 mL of methanol, ultrasonically dissolve febantel, let it cool, dilute to the scale with methanol, and shake well; filter through a 0.22 μm filter membrane into an injection vial, and detect by high-performance liquid chromatography. Detection conditions: Chromatographic column: C18 4.6 × 250 mm, 5 μm; Detector: SPD-16C; Mobile phase: Acetonitrile: water (60:40); Column temperature: 30 °C; Detection wavelength: 295 nm; Flow rate: 1.0 mL / min; Injection volume: 10 μL.

[0081] 2 Test results: The sedimentation results of Examples 1-6 and Comparative Examples 1-3 in water are shown in Table 3. From Table 3, we can see that after the fenbendazole powder of Examples 1-6 was dissolved in water for 4 hours, the content of fenbendazole in water was still above 90%; the formulation of Comparative Example 1 was the same as that of Example 2, only the production process was different. When placed for 4 hours, the content of fenbendazole in water in Comparative Example 1 was 20% lower than that in Example 2. The production processes of Comparative Example 2 and Comparative Example 3 were similar to those of Examples 1-6, but the ionic surfactant sodium dodecyl sulfate was used. When placed for 4 hours, the content of fenbendazole in water was only about 50%-60%, which was significantly lower than 90% of the product of this invention patent. The above results show that: The fenbendazole dry mixture prepared according to this invention patent has good suspension and is not easy to sediment in water.

[0082] Table 3 Detection results of fenbendazole content in sedimentation test

[0083]

[0084]

[0085] Test Example 3 Safety evaluation test of fenbendazole dry suspension in poultry 1 Test materials

[0086] Test animals: White - feather broilers, 14 days old.

[0087] Test drugs: Samples of Examples 1-6 and Comparative Examples 1-3.

[0088] Test grouping: Blank control group, and for each drug group, the recommended dose (1 - fold dose), medium dose (3 - fold dose), and medium - high dose (5 - fold dose) were designed, with 10 chickens in each group.

[0089] Dosing dose: Calculated based on the fenbendazole raw material, 0.05 g / kg (since the content of fenbendazole in Examples 1-6 is inconsistent, conversion is required during the test), administered by drinking water.

[0090] 2 Test methods

[0091] One - day - old chicks were normally raised until 14 days. According to the body weight of each group of chickens, the dosing amount and the drug - containing drinking water volume of each group of chickens were calculated according to the above dosing dose and recorded. Each chicken needed to be weighed one by one after the test. After dosing, observe continuously for 7 days, drink water without added drugs, and on the 7th day after the end of dosing, conduct necropsy. Clinical observation was carried out throughout the feeding cycle.

[0092] 3 Test results

[0093] By analyzing the relative weight gain rate, daily feed intake, and daily water intake of chickens before and after drug administration, the relative weight gain rates of each drug administration group in Examples 1-6 and Comparative Examples 1-3 were all above 97%, and there were no significant differences in feed intake and water intake compared with the control group. Clinical symptoms were observed daily, and no abnormalities were found in the clinical symptoms of chickens in each group, such as spirit, respiration, digestion, etc. This indicates that the fenbendazole dry suspension prepared by the present invention has good safety.

[0094] Table 4 Relative weight gain rate of chickens

[0095]

[0096]

[0097]

[0098] Table 5 Daily feed intake of chickens in each group

[0099]

[0100]

[0101] Table 6 Daily water intake of chickens in each group

[0102]

[0103]

[0104]

[0105] Test Example 4 Observation on the effect of fenbendazole powder dry suspension in expelling nematodes in pigs

[0106] In order to further verify the drug efficacy of the present invention, in March 2023, an observation test on the prevention and treatment effect of the drug of the present invention on nematodes in pigs was carried out in a pig farm in Henan.

[0107] 1 Test materials

[0108] 1.1 Test animals

[0109] From the pigs naturally infected, 200 pigs with similar body weights were selected and randomly divided into 10 groups, with 20 pigs in each group.

[0110] 1.2 Test drugs

[0111] Drugs prepared in Examples 1-6 and Comparative Examples 1-3.

[0112] 1.3 Test grouping

[0113] Two hundred selected experimental animals were randomly divided into 10 groups, with 20 animals in each group. Group 1 of the experiment was the control group, a group without drug administration under natural infection. Groups 2 - 7 of the experiment were groups administered with the drugs prepared in Examples 1 - 6 of the present invention patent, and groups 8 - 10 of the experiment were groups administered with the drugs prepared in Comparative Examples 1 - 3 of the present invention patent.

[0114] 1.4 Dosage

[0115] Calculated based on the raw material of fenbendazole, the drug was administered by drinking water at a dose of 6 mg / kg body weight. Each group was separately isolated and raised under the same feeding conditions.

[0116] 2 Test method

[0117] 4 hours before the test, the pigs were deprived of water and feed. They were weighed and the body weight was recorded. The dosage of the drug for each pig was calculated according to the body weight, and the drug was added to the water for drinking. For the control group, an equal amount of water was given. On the day of drug administration (day 0, before drug administration) and on the 7th and 14th days after drug administration, the feces of the pigs in each group were collected. After mixing evenly, the fecal egg count was performed using the McMaster technique to calculate the infection quantity.

[0118] 2.2 Efficacy determination criteria

[0119] The changes in nematodes and eggs in the feces of pigs in each group before and after deworming were statistically analyzed. The reduction rate of nematodes and eggs in the feces was greater than or equal to 90%, and the physical signs of the experimental animals returned to normal. Secondly, it was observed whether the clinical symptoms (diarrhea, emaciation, changes in fecal traits, vomiting, etc.) disappeared. The reduction rate of eggs was mainly statistically analyzed, and the deworming effect was calculated according to the following formula:

[0120] Egg reduction rate (%) = (number of eggs per gram of feces before the test - number of eggs per gram of feces after the test) / number of eggs per gram of feces before the test × 100%.

[0121] 3 Test results

[0122] There were no adverse reactions in the pigs after the administration of Examples 1 - 6 and Comparative Examples 1 - 3, and the fecal state of the pigs gradually became normal. The skin color gradually became ruddy and the hair became shiny.

[0123] The results of deworming gastrointestinal nematodes in pigs of Examples 1 - 6 and Comparative Examples 1 - 3 are shown in Table 7. It can be seen from this table that the fenbendazole dry suspension prepared according to the present invention (Examples 1 - 6) and Comparative Examples 1 - 3 both have good nematode - expelling effects, and the deworming effect of the fenbendazole dry suspension prepared by the present invention is slightly better than that of the comparative examples.

[0124] Table 7 Examination results of digestive tract nematodes and eggs in pig feces before and after drug administration

[0125]

[0126]

[0127] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A febantel dry suspension, characterized in that: The dry suspension is prepared from the following components in parts by weight: 3-10 parts of fenbendazole, 2-10 parts of suspending agent, 2-10 parts of non-ionic surfactant, 3-5 parts of dispersant, 70-90 parts of carrier, 3-10 parts of solvent, and 0.01-2 parts of antioxidant.

2. The fenbendazole dry suspension according to claim 1, characterized in that: The dry suspension is prepared from the following components in parts by weight: 3-5 parts of fenbendazole, 5-10 parts of suspending agent, 2-5 parts of non-ionic surfactant, 3-4 parts of dispersant, 80-90 parts of carrier, 5-10 parts of solvent, and 0.01-1 part of antioxidant.

3. The fenbendazole dry suspension according to claim 2, wherein: The dry suspension is prepared from the following components in parts by weight: 5 parts of fenbendazole, 10 parts of suspending agent, 5 parts of non-ionic surfactant, 3 parts of dispersant, 80 parts of carrier, 10 parts of solvent, and 0.1 part of antioxidant.

4. The fenbendazole dry suspension according to any one of claims 1 to 3, characterized in that: The non-ionic surfactant is selected from one or more of the following: Tween-40, Tween-60, Tween-80, Myrj-49, Myrj-51, Myrj-52, polyoxyethylene hydrogenated castor oil 35, polyoxyethylene hydrogenated castor oil 40, polyoxyethylene hydrogenated castor oil 50, hydrogenated castor oil 35, hydrogenated castor oil 40.

5. The fenbendazole dry suspension according to any one of claims 1 to 3, characterized in that: The suspending agent is selected from one or more of the following: gum arabic, xanthan gum, sodium alginate, methyl cellulose, β-cyclodextrin, hydroxypropyl methyl cellulose, sodium carboxymethyl cellulose, konjac gum, hydroxypropyl β-cyclodextrin, thickening agent.

6. The fenbendazole dry suspension according to any one of claims 1 to 3, characterized in that: The dispersant is selected from one or more of the following: trisodium phosphate, silica, polyvinylpyrrolidone, polyethylene glycol 4000, polyethylene glycol 6000.

7. The fenbendazole dry suspension according to any one of claims 1 to 3, characterized in that: The carrier is selected from one or more of the following: soluble starch, anhydrous glucose, lactose, maltodextrin.

8. The fenbendazole dry suspension according to any one of claims 1 to 3, characterized in that: The solvent is selected from one or more of the following: water, ethanol, ethyl acetate.

9. The fenbendazole dry suspension according to any one of claims 1 to 3, characterized in that: The antioxidant is selected from one or more of the following: sodium bisulfite, sodium metabisulfite, anhydrous sodium sulfate, potassium sorbate, gallate, butylated hydroxyanisole, 2,6-di-tert-butyl-4-methylphenol, tert-butylhydroquinone.

10. The preparation method of the fenbendazole dry suspension according to any one of claims 1 to 3, characterized in that, The fenbendazole dry suspension is prepared by the following steps: (1) Pretreatment of fenbendazole: After mixing the non-ionic surfactant and the solvent evenly, add the fenbendazole raw material, stir evenly, dry, crush, and pass through a No. 5 sieve for standby. (2) Add the treated fenbendazole, suspending agent, carrier, dispersant, and antioxidant into a mixer and mix evenly to obtain the fenbendazole dry suspension.

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