CN111714470A

CN111714470A - Sustained-release ethylenediamine tetraacetic acid iron sodium premix for animals and preparation method thereof

Info

Publication number: CN111714470A
Application number: CN202010459417.XA
Authority: CN
Inventors: 刘华山; 刘爱玲; 葛冰; 李守军; 吴燕子; 乔博鑫; 朱广月; 崔广超; 谢玲玲
Original assignee: Tianjin Ruiyiruimei Biotechnology Co ltd
Current assignee: Ringpu Hi-Tech (Tianjin) Biotechnology Co., Ltd.
Priority date: 2020-05-27
Filing date: 2020-05-27
Publication date: 2020-09-29
Anticipated expiration: 2040-05-27
Also published as: CN111714470B

Abstract

The invention relates to a veterinary sustained-release ethylenediamine tetraacetic acid ferric sodium premix and a preparation method thereof, belonging to the technical field of veterinary drugs. The ethylenediamine tetraacetic acid iron sodium premix comprises the following components in parts by weight: 2-8% of sodium ferric ethylenediamine tetraacetate, 1-15% of coating agent, 0.5-1% of flavoring agent, 2-5% of synergist and diluent which are supplemented to 100%. The ethylenediamine tetraacetic acid iron sodium premix is an enteric sustained-release pellet prepared by coating an enteric sustained-release coating agent, can effectively reduce the stress of a common iron supplement agent on an animal organism, has obvious sustained-release effect, and has a good effect of improving the hemoglobin content in the bodies of weaned piglets.

Description

Sustained-release ethylenediamine tetraacetic acid iron sodium premix for animals and preparation method thereof

Technical Field

The invention belongs to the technical field of veterinary medicines, and particularly relates to a veterinary slow-release ethylenediamine tetraacetic acid ferric sodium premix and a preparation method thereof.

Background

Iron is used as an essential trace element of livestock and poultry, has very important effect in breeding production, and has important effect on sow production performance, piglet growth and development, metabolic process and physiological defense function. Iron is a cofactor of peroxidase (CAT) in the body's antioxidant system and plays an important role in preventing lipid oxidation and maintaining meat flavor.

The development of the livestock iron supplement agent goes through 3 stages, the first stage is inorganic salts, which are commonly used as ferrous sulfate, ferrous carbonate and the like, and the iron supplement agent is widely applied for a long time due to low cost, but inorganic iron sources are easy to absorb moisture, agglomerate and damage vitamins in feed, so that the iron absorption and utilization rate is low, and certain pollution is caused to the environment; the second generation is simple organic salts, such as ferrous citrate, ferric fumarate and the like, but the biological value of the 2 types is low, the other components in the feed can be influenced, and meanwhile, with the gradual enhancement of environmental awareness of people, researchers are promoted to develop more effective and safer iron supplement preparations; therefore, the iron preparation has the advantages of good chemical stability, high bioavailability, no irritation, no toxic or side effect and the like, can supplement iron to the suckling pigs in the fetal period by reaching the placenta through the umbilical cord, and has a clinical application effect remarkably superior to that of the first 2 generations of products.

The latest iron supplement products are amino acid chelated iron, such as methionine chelated iron, threonine chelated iron and the like, but have the defects of more free iron ions, poor mouthfeel, heavy iron fishy smell and the like. Sodium iron ethylenediaminetetraacetate (NaFeEDTA) is a metal chelate, is also an oral patch enhancer used by WHO for promotion, has no iron rust taste, and is widely applied to human food. The sodium iron ethylene diamine tetraacetate is light earthy yellow crystalline powder, has stable property, high temperature resistance, difficult oxidation, unchanged storage, no metallic iron fishy smell, good taste, easy water solubility and little sensory modification caused by application in food. The stable chelate structure has no stimulation to the stomach and intestine, EDTA can be combined with harmful elements to be quickly excreted to play a role of an antidote in the absorption process, phytic acid and the like can be avoided from obstructing the absorption of an organism, researches show that the absorption rate of the sodium ferric EDTA is 2-3 times of that of ferrous sulfate, the sodium ferric EDTA also has the effect of promoting the absorption of other iron sources or endogenous iron sources in diet, and can promote the absorption of zinc without influencing the absorption of calcium.

The pellet is spherical solid with diameter less than 2.5mm composed of medicinal powder and adjuvants, and can be coated with delayed release coating or lipid and wax substances such as fatty acid, fatty alcohol, esters, and waxes. The method is divided into the following steps according to the drug release speed: quick release pellets and sustained and controlled release pellets. The sustained and controlled release pellet is mainly characterized in that: the medicine is mainly absorbed in small intestine after administration, has high bioavailability, no influence of gastric emptying, and good fluidity. The coated pellet has the advantages of improving the stability of the drug, changing the drug release rate, avoiding the stress caused by the injection and the like.

In the production practice, the pig is mainly injected with the hemoth to supplement iron so as to meet the growth requirement of the pig. However, for large-scale breeding, not only is a lot of time and labor consumed by iron supplement through injection, but also a large amount of stress is generated when the injection dosage is too large, so that iron overload is caused to piglets, and oxidative stress and iron malabsorption and even death of the piglets are caused.

Therefore, the development of an iron supplement agent which is suitable for large-scale cultivation and has good iron supplement effect, small stress, safety and reliability is an urgent need of the cultivation industry.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a safe, effective and high-yield veterinary sustained-release ethylenediaminetetraacetic acid ferric sodium premix.

On the one hand, the invention provides a sustained-release ethylenediamine tetraacetic acid iron sodium premix for animals, which comprises the following components in percentage by mass: 2-8% of sodium ferric ethylenediamine tetraacetate, 1-15% of coating agent, 0.5-1% of flavoring agent, 2-5% of synergist and diluent which are supplemented to 100%. Preferably, the weight percentages of the components are as follows: 3-6% of sodium ferric ethylenediamine tetraacetate, 4-9% of coating agent, 0.6-0.8% of flavoring agent, 3-4.5% of synergist and diluent which are supplemented to 100%. More preferably, the mass percentages of the components are as follows: 5% of sodium ferric ethylenediamine tetraacetate, 8% of coating agent, 0.7% of flavoring agent, 4% of synergist and 100% of diluent.

The diluent is one or more of anhydrous glucose, starch, silicon dioxide, lactose and microcrystalline cellulose, and is preferably one or combination of microcrystalline cellulose and lactose.

The coating agent is an enteric slow-release coating agent, and the coating agent comprises the following components in percentage by mass: 17.5-35% of mixture of acrylic resin II and acrylic resin III, 7.5-15% of polyethylene glycol, 10-20% of seaweed gel, 5-10% of talcum powder, 5-12% of methyl silicone oil, 15-20% of hydrogenated soybean oil and 15-18% of castor oil (the sum of the weight percentages of the raw materials of the coating agent is 100%), and 95% of ethanol is used as a coating solvent; preferably 30% of a mixture of acrylic resins II and III, 10% of polyethylene glycol, 10% of seaweed gel, 10% of talcum powder, 10% of methyl silicone oil, 15% of hydrogenated soybean oil and 15% of castor oil, and 95% of ethanol is used as a coating solvent. The acrylic resins II and III in the mixture of acrylic resins II and III may be mixed in any ratio, preferably 1: 1.

The flavoring agent is one or more of aspartame, thaumatin and saccharin sodium, preferably one or a combination of thaumatin and saccharin sodium.

The synergist is plant extract, and is one or more of garlicin, oregano oil, peppermint essence, rosemary extract, tea polyphenol and cinnamaldehyde, preferably one or more of garlicin and rosemary extract.

On the other hand, the invention also provides a preparation method of the sustained-release ethylenediamine tetraacetic acid iron sodium premix for livestock, which is characterized by comprising the following steps:

(1) weighing the sodium ferric ethylenediamine tetraacetate, the diluent, the coating agent, the flavoring agent and the synergist according to the weight parts for later use, and respectively sieving the sodium ferric ethylenediamine tetraacetate and the diluent with a 65-mesh sieve for later use.

(2) Mixing sodium ferric ethylenediamine tetraacetate, diluent and correctant uniformly, wetting and extruding by using water in an extruder to make granules, then further making ball-blasting and forming by using ball-blasting machine to obtain the invented micropill.

(3) And (3) transferring the pellets prepared in the step (2) into a fluidized bed, blowing air flow with the temperature of 45-60 ℃, then spraying a synergist to uniformly mix the materials in a fluidized state, repeatedly spraying and drying until the particle size is about 2mm, stopping spraying, continuously drying the formed particles in the fluidized bed, and keeping the moisture of the particles within 5%.

(4) And (4) putting the granules obtained in the step (3) into a coating machine, spraying a coating sustained-release agent, coating for 30 minutes, and discharging.

(5) Sieving, and collecting 10-40 mesh coated pellet to obtain the premix.

Has the advantages that:

1. the sustained-release animal premix is prepared by performing enteric coating on the ethylenediaminetetraacetic acid ferric sodium salt, the optimal process is selected, the product has stable property and good fluidity, and the effect on preventing and treating the anemia of the livestock and poultry is obvious.

2. After the sodium ferric ethylenediamine tetraacetate is coated by the enteric coating agent, the iron rust taste is avoided, the defects of poor palatability, overlarge stress and the like of the existing iron supplement preparation can be effectively overcome, and the administration of livestock and poultry groups is convenient. Meanwhile, the enteric sustained-release preparation prolongs the action time of the medicament and plays a long-acting and sustained-release role. The product has the advantages of no loss of effective components during storage, transportation and application, and high quality stability.

3. The product of the invention has obvious iron supplementing effect on livestock and poultry, and can increase the feed intake of livestock and poultry, reduce the feed conversion ratio and diarrhea rate, thereby improving the growth performance and survival rate of livestock and poultry.

Detailed Description

The foregoing will be described in further detail by way of specific embodiments in the form of examples. This should not be construed as limiting the scope of the above-described subject matter to the following examples. All techniques implemented based on the teachings of the present invention are within the scope.

Example 1

The embodiment provides a sustained-release ethylenediamine tetraacetic acid ferric sodium premix for animals, wherein each 1kg of the premix contains 20g of ethylenediamine tetraacetic acid ferric sodium, 10g of coating agent, 5g of aspartame, 10g of origanum oil, 10g of allicin and 945g of starch.

Example 2

The embodiment provides a sustained-release ethylenediamine tetraacetic acid ferric sodium premix for animals, wherein each 1kg of the premix contains 30g of ethylenediamine tetraacetic acid ferric sodium, 40g of coating agent, 6g of saccharin sodium, 20g of rosemary extract, 10g of allicin and 894g of lactose.

Example 3

The embodiment provides a sustained-release ethylenediamine tetraacetic acid ferric sodium premix for animals, wherein each 1kg of the premix contains 60g of ethylenediamine tetraacetic acid ferric sodium, 90g of coating agent, 8g of thaumatin, 25g of rosemary extract, 20g of allicin and 797g of microcrystalline cellulose.

Example 4

The embodiment provides a sustained-release ethylenediamine tetraacetic acid ferric sodium premix for animals, wherein each 1kg of the premix contains 50g of ethylenediamine tetraacetic acid ferric sodium, 80g of coating agent, 4g of thaumatin, 3g of saccharin sodium, 20g of rosemary extract, 20g of allicin, 500g of microcrystalline cellulose and 323g of lactose.

Example 5

The embodiment provides a sustained-release ethylenediamine tetraacetic acid ferric sodium premix for animals, wherein each 1kg of the premix contains 80g of ethylenediamine tetraacetic acid ferric sodium, 150g of coating agent, 10g of saccharin sodium, 20g of mint essence, 30g of tea polyphenol and 710g of anhydrous glucose.

The preparation process of the ethylenediaminetetraacetic acid ferric sodium salt premix described in the above embodiments 1-5 comprises the following steps:

(4) Preparing enteric coating solution by using 95% ethanol: the coating agents required for each example were formulated according to the formulations of table 1.

(5) And (4) putting the granules obtained in the step (3) into a coating machine, spraying a coating agent for coating for 30 minutes, and discharging.

(6) Sieving, and collecting 10-40 mesh coated pellet to obtain the premix.

TABLE 1 compositions of each of the coating agents of examples 1-5

Coating agent composition	Example 1	Example 2	Example 3	Example 4	Example 5
						Acrylic resins II, III mixtures (g)	3	7	20	24	52
Polyethylene glycol (g)	1	6	7	8	12
						Seaweed glue (g)	1	8	14	8	21
Talcum powder (g)	1	3.5	7	8	10
						Methyl silicone oil (g)	1	3.5	10.5	8	10
Hydrogenated Soybean oil (g)	1.5	6	17.5	12	22.5
						Castor oil (g)	1.5	6	14	12	22.5
Total up to	10	40	90	80	150

Comparative example 1

The embodiment provides a sustained-release ethylenediamine tetraacetic acid ferric sodium premix for animals, and each 1kg of the premix contains 50g of ethylenediamine tetraacetic acid ferric sodium, 80g of coating agent, 4g of thaumatin, 3g of saccharin sodium, 20g of rosemary extract, 20g of allicin, 500g of anhydrous glucose and 323g of starch.

Comparative example 2

The embodiment provides a sustained-release ethylenediamine tetraacetic acid ferric sodium premix for animals, and each 1kg of the premix contains 50g of ethylenediamine tetraacetic acid ferric sodium, 80g of coating agent, 4g of thaumatin, 3g of saccharin sodium, 20g of tea polyphenol, 20g of cinnamaldehyde, 500g of microcrystalline cellulose and 323g of lactose.

The coating agent composition and the premix in comparative examples 1 and 2 are prepared as in example 4 of the present invention.

The average values of the water content and fluidity (in terms of angle of repose) results of the ethylenediaminetetraacetic acid iron sodium premix prepared in inventive examples 1-5 and comparative example 1 are shown in table 2.

Table 2 premix moisture and flowability test results

Sample name	Average water content%	Mean angle of repose (°)
			Example 1	3.69	28.6
Example 2	2.73	21.4
			Example 3	2.76	24.2
Example 4	2.44	19.3
			Example 5	3.35	30.2
Comparative example 1	3.12	26.8

From the results in Table 2, it can be seen that the EDTA iron sodium premix of examples 2-4 of the present invention has lower water content and better flowability. In particular, the premix of example 4 had the lowest moisture content and the best flowability. And compared with the comparative example 1 (taking anhydrous glucose and starch as diluents), the premix in the embodiment 4 of the invention (when the diluents are compounded by microcrystalline cellulose and lactose) has obviously lower water content and better flowability.

Experimental example 1 palatability experiment

The experimental method comprises the following steps: selecting 120 healthy weaned piglets with weight of 15kg +/-5 kg, randomly and averagely dividing into 8 groups, wherein 15 piglets in each group are respectively I, II, III, IV, V, VI, VII and VIII groups. In groups I-VI, the sodium iron ethylenediaminetetraacetate premix prepared in examples 1-5 and comparative example 2 was administered, and 1kg of the sustained-release sodium iron ethylenediaminetetraacetate premix was added to every 100kg of the feed for 5 days; feeding the raw material medicament of the sodium iron ethylenediaminetetraacetate into the group VII in a mixed way, adding 0.5kg of the raw material medicament of the sodium iron ethylenediaminetetraacetate into every 100kg of feed, and continuously using for 5 days; group VIII is a blank control group, no drug is administered, and normal feeding management is the same as that of groups I-VII.

The palatability test results are shown in table 3.

Table 3 palatability test results of the premix

	Group I	Group II	Group III	Group IV	Group V	Group VI	Group VII	Group VIII
									Average daily food intake (g/head)	546.7	553.1	560.4	570.6	548.7	540.9	495.2	516.8

And (4) experimental conclusion:

the palatability of the ethylenediamine tetraacetic acid ferric sodium premix is good, and particularly, the compound feed intake taking rosemary extract and allicin as synergists is the best (examples 2-4). And as can be seen from the experimental data, compared with the comparative example 2 (the synergist is tea polyphenol and cinnamaldehyde), the feed intake in example 4 is obviously better.

Experimental example 2 measurement of in vitro simulated Release Effect

The experimental method comprises the following steps: the dissolution rate of the sample is measured by adopting a slurry method in a dissolution instrument, dissolution media are artificial gastric juice and artificial intestinal juice respectively, the volume is 800ml, the rotating speed of a motor is 120r/min, and the temperature is 37 ℃. After the temperature of the dissolution medium is constant, 20g of the sample of the embodiment 1-5 of the invention is taken and added into the adjusted dissolution medium, the timing is 4 hours, the sample is taken, the ferric sodium ethylenediamine tetraacetate in the dissolution liquid is measured, and the dissolution rate is calculated.

Preparing artificial gastric juice: taking 16.4ml of dilute hydrochloric acid, adding about 800ml of water and 10g of pepsin, shaking up, and adding water to dilute into 1000ml to obtain the finished product.

Preparing artificial intestinal juice: dissolving potassium dihydrogen phosphate 6.8g in water 500ml, adjusting pH to 6.8 with 0.1mol/L sodium hydroxide solution, dissolving pancreatin 10g in water, mixing the two solutions, and diluting with water to 1000 ml.

The results of the in vitro simulated release of the samples of examples 1-5 are shown in Table 4.

TABLE 4 dissolution Rate results for samples

And (4) experimental conclusion:

the ethylenediaminetetraacetic acid ferric sodium salt premix prepared according to embodiments 1-5 of the invention has obvious slow release effect, is not released and damaged in gastric juice, has high release speed in intestinal juice, and can be fully absorbed and utilized by organisms.

Experimental example 3 Effect of iron supplement on growth and iron supplement effect of piglets

The experimental method comprises the following steps: 160 ternary hybrid weaned piglets are randomly divided into 8 groups, and each group comprises 20 piglets, wherein the 1 st group is mixed and fed with the ferric sodium ethylenediamine tetraacetate premix prepared in the example 4, 1kg of self-made ferric sodium ethylenediamine tetraacetate premix is added into each ton of feed, the continuous feeding is carried out for 7 days, and then the normal daily ration is fed for free feeding; group 2 commercial product 1 (iron glycinate chelate as the main ingredient) was given; group 3 commercial product 2 (iron glycinate as the main ingredient) was given; group 4 was given commercial product 3 (ferrous citrate as the main ingredient); group 5 commercial product 4 (ferrous fumarate as the major ingredient) was administered; group 6 was given commercial product 5 (ferrous sulfate as the main ingredient); in group 7, a commercial product 6 (iron dextran injection) is given, 3mL of iron dextran injection is injected into each piglet, and the piglet is fed with normal daily ration freely; the 8 th group is a blank control group, iron is not supplemented, and the normal daily ration is given for free ingestion; the administration dose and feeding management of groups 2-6 were the same as those of group 1. Blood is collected on 0 th, 1 th, 2 th, 5 th, 7 th, 9 th, 12 th and 15 th days after the test is started in each test group to measure the in vivo hemoglobin content of the test group, the sick head number and the dead head number of the piglets are recorded in detail in the test observation period (15 days), and the weight gain and the in vivo hemoglobin content value difference between the test group and the control group are compared by using a t test to determine whether the difference is obvious or not.

The experimental results are as follows: the results of the growth promotion experiment of the weaned piglets are shown in the table 5 and the table 6.

TABLE 5 growth promoting Effect of iron supplement on weaned piglets

Table 6 hemoglobin (Hb) of weaned piglets at different day ages: g/L

Group of

Day 0

1 day

2 days

5 days

7 days

9 days

12 days

15 days

Group 1

86.34±4.15

91.45±6.72

95.37±5.39

103.45±8.31

109.19±6.52

108.86±7.64

112.42±9.73

118.37±10.85

2 groups of

82.67±3.28

88.37±7.31

102.33±8.86

114.74±6.49

107.12±5.16

101.44±7.63

104.37±3.45

90.48±5.93

Group 3

79.34±4.47

86.46±9.36

95.78±10.42

102.43±5.18

107.64±4.27

111.28±8.31

110.59±5.52

93.46±7.39

4 groups of

87.69±5.31

93.83±3.35

97.16±8.24

104.49±6.52

109.37±4.40

100.64±6.39

94.43±7.25

88.34±6.49

5 groups of

85.79±3.32

91.43±5.65

97.36±6.83

104.34±5.68

117.37±4.94

102.97±8.32

91.37±6.86

90.73±7.88

6 groups of

80.46±6.45

92.31±1.92

97.35±11.69

110.62±9.34

112.68±6.76

96.43±5.35

95.81±8.79

98.61±7.24

7 groups of

79.33±3.92

123.87±6.18

119.35±7.72

109.32±4.37

97.15±9.73

104.37±3.25

98.34±5.67

93.18±12.46

8 groups of

83.76±6.63

83.49±4.37

86.18±5.25

87.11±3.29

88.73±9.48

85.36±8.45

90.35±8.80

94.16±8.37

And (4) experimental conclusion:

according to the sodium iron ethylenediaminetetraacetate premix (experiment group 1) prepared in the embodiment 4 of the invention, after the continuous administration for 7 days, the administration is stopped until the monitoring period of 15 days is finished, the hemoglobin content in the piglets can still maintain a higher level, the slow-release effect is very obvious, the premix is superior to the similar iron supplement preparation sold in the market, the diarrhea rate and the death rate of the weaned piglets can be effectively reduced, and the feed conversion ratio is remarkably reduced.

After the piglets in the experimental group 7 are injected with the iron supplement, the hemoglobin content in the body is rapidly increased in a short time, the hemoglobin content in the body is rapidly reduced after the administration, and the high level is difficult to maintain, but the administration mode easily causes iron supplement overload to generate adverse stress, and the pigs can die in severe cases. The experimental result shows that the product of the invention can effectively improve the hemoglobin content in the body of the weaned pig and improve the growth performance of the weaned pig, has obviously better effect than the existing iron supplement agent sold in the market, and has wide application prospect.

Claims

1. The sustained-release ethylenediamine tetraacetic acid iron sodium premix for the animals is characterized by comprising the following components in percentage by mass: 2-8% of sodium ferric ethylenediamine tetraacetate, 1-15% of coating agent, 0.5-1% of flavoring agent, 2-5% of synergist and diluent which are supplemented to 100%.

2. The ethylenediaminetetraacetic acid iron sodium salt premix as in claim 1, wherein the premix comprises the following components by mass percent: 3-6% of sodium ferric ethylenediamine tetraacetate, 4-9% of coating agent, 0.6-0.8% of flavoring agent, 3-4.5% of synergist and diluent which are supplemented to 100%.

3. The ethylenediaminetetraacetic acid ferric sodium salt premix as in claim 1 or 2, wherein the premix comprises the following components by mass percent: 5% of sodium ferric ethylenediamine tetraacetate, 8% of coating agent, 0.7% of flavoring agent, 4% of synergist and 100% of diluent.

4. The ethylenediaminetetraacetic acid ferric sodium salt premix according to any one of claims 1-3, wherein the diluent is one or more of anhydrous glucose, starch, silicon dioxide, lactose, and microcrystalline cellulose.

5. The ethylenediaminetetraacetic acid ferric sodium salt premix of claim 4, wherein the diluent is one or a combination of microcrystalline cellulose and lactose.

6. The ethylenediaminetetraacetic acid ferric sodium salt premix of any one of claims 1-3, wherein the flavoring agent is one or more of aspartame, thaumatin and saccharin sodium; the synergist is plant extract, and is one or more of garlicin, origanum oil, herba Menthae essence, herba Rosmarini officinalis extract, tea polyphenols, and cinnamaldehyde.

7. The ethylenediaminetetraacetic acid ferric sodium salt premix of claim 6, wherein, the flavoring agent is one or the combination of thaumatin and saccharin sodium; the synergist is one or combination of allicin and rosemary extract.

8. The ethylenediaminetetraacetic acid ferric sodium salt premix according to any one of claims 1-3, wherein the coating agent is an enteric sustained release coating agent; the coating agent comprises the following components in percentage by mass: 17.5-35% of mixture of acrylic resin II and acrylic resin III, 7.5-15% of polyethylene glycol, 10-20% of seaweed gel, 5-10% of talcum powder, 5-12% of methyl silicone oil, 15-20% of hydrogenated soybean oil, 15-18% of castor oil and 95% ethanol as a coating solvent.

9. The ethylenediaminetetraacetic acid iron sodium salt premix according to claim 8, wherein the coating agent comprises, by weight, 30% of a mixture of acrylic resins II and III, 10% of polyethylene glycol, 10% of seaweed gel, 10% of talcum powder, 10% of methyl silicone oil, 15% of hydrogenated soybean oil, 15% of castor oil, and 95% of ethanol as a coating solvent.

10. A method for preparing the sustained-release ethylenediaminetetraacetic acid ferric sodium salt premix for animals as claimed in any one of claims 1-9, which comprises the following steps:

(1) weighing sodium ferric ethylenediamine tetraacetate, a diluent, a coating agent, a flavoring agent and a synergist according to the mass parts for later use, and respectively sieving the sodium ferric ethylenediamine tetraacetate and the diluent with a 65-mesh sieve for later use;

(2) uniformly mixing sodium ferric ethylenediamine tetraacetate, a diluent and a flavoring agent, wetting and extruding the mixture by using water in an extruder to prepare granules, and further performing shot blasting and molding by using a shot blasting machine to prepare pellets;

(3) transferring the pellets prepared in the step (2) into a fluidized bed, blowing air flow with the temperature of 45-60 ℃, then spraying a synergist to uniformly mix the materials in a fluidized state, repeatedly spraying and drying until the particle size is about 2mm, stopping spraying, continuously drying the formed particles in the fluidized bed, and keeping the moisture of the particles within 5%;

(4) putting the granules obtained in the step (3) into a coating machine, spraying a coating sustained-release agent for coating for 30 minutes, and discharging;

(5) sieving, and collecting 10-40 mesh coated pellet.