A compound astragalus polysaccharide injection for veterinary use and its production process

Abstract

The present invention discloses a veterinary compound astragalus polysaccharide injection and its production process, belonging to the technical field of veterinary pharmaceutical preparations, which includes the following steps: dissolving astragalus polysaccharide and then compounding it with composite nanoparticles to obtain astragalus polysaccharide-loaded powder; adding a surfactant and absolute ethanol to liquid paraffin, adding the dispersion to the reaction kettle while stirring, and then stirring to obtain the veterinary compound astragalus polysaccharide injection; in the production process of the present invention, cyclodextrin is prepared into a carrier to adsorb and encapsulate astragalus polysaccharide, and the adsorption ability of the cyclodextrin carrier is used to form a core-shell structure with polylactic acid, and the polylactic acid coated with nano-selenium is loaded in the cyclodextrin carrier, which not only prevents the aggregation of nano-selenium in the injection, but also improves the dispersibility of astragalus polysaccharide. By preparing the composite nanoparticles into an emulsion, the dispersibility of the composite nanoparticles is improved, and the injection in the form of an emulsion is more easily absorbed by animals, enabling nano-selenium and astragalus polysaccharide to produce a synergistic effect and improve the resistance of animals.

Description

Technical Field

[0001] The present invention belongs to the technical field of veterinary pharmaceutical preparations, and particularly relates to a veterinary compound astragalus polysaccharide injection and its production process. Background Art

[0002] Astragalus polysaccharide is the most important natural active ingredient in astragalus, and is a class of macromolecular compounds that play a decisive role in the pharmacological effects of astragalus. Astragalus polysaccharide can improve the body's immune function, enhance cell physiological metabolism, and increase the activity of macrophages. It is an ideal immune enhancer. Astragalus polysaccharide injection is a relatively ideal, safe and effective preparation at present, which has a significant effect on improving the immunity of animals, can effectively reduce the outbreak and transmission of epidemic diseases in the breeding industry, and provide guarantee for the livestock breeding industry.

[0003] Patent CN102198152A discloses a pig injection containing astragalus polysaccharide iron and its preparation method. Guided by nanotechnology, using astragalus polysaccharide and trivalent iron salt as the main raw materials, through synthesizing hydroxy iron oxide iron mother nucleus, and then complexing with alkalized astragalus polysaccharide ligand, refining, formulating and sterilizing to obtain astragalus polysaccharide iron injection, which can effectively enhance the body's immunity and improve the survival rate of piglets. However, this scheme uses astragalus polysaccharide to disperse iron ions in the injection to improve the utilization rate of iron ions by piglets, and has a low synergistic effect with astragalus polysaccharide.

[0004] Patent CN105456185A discloses a compound astragalus polysaccharide injection and its preparation method. By adding water-soluble polymer material PVPk30 and polyethylene glycol to increase the solution viscosity, reduce the drug diffusion rate, and prolong the action time, and by selecting two different sources of natural polysaccharides, astragalus polysaccharide and α-mannan peptide, to be compounded, the immune enhancement effect can be effectively exerted. However, after using polyethylene glycol to increase the solution viscosity in this scheme, it is easy to cause the reduction of polysaccharide solubility, easy to produce precipitation, not easy to absorb, resulting in poor injection effect, and not conducive to storage and transportation.

[0005] There is a need for a stable dispersion of astragalus polysaccharide, which is conducive to storage and transportation, and at the same time has a good injection effect and a good absorption effect of astragalus polysaccharide, so as to improve the immunity of animals and promote the growth of animals. Summary of the Invention

[0006] One of the purposes of the present invention is to solve how to improve the stable dispersion of astragalus polysaccharide in astragalus polysaccharide injection, and provide a veterinary compound astragalus polysaccharide injection and its production process.

[0007] The second purpose of the present invention is to solve how to improve the absorption effect of the compound astragalus polysaccharide injection in animals and the animal immunity, and provide a veterinary compound astragalus polysaccharide injection and its production process.

[0008] The object of the present invention can be achieved by the following technical solutions:

[0009] A production process of a compound astragalus polysaccharide injection for veterinary use, comprising the following steps:

[0010] Step 1: Dissolve astragalus polysaccharide in deionized water in a reaction kettle, add composite nanoparticles into the reaction kettle, stir for 40 - 48 h, centrifuge to collect the precipitate, wash the precipitate with ethanol, and then vacuum dry at 40 - 50 °C for 10 - 12 h to obtain astragalus polysaccharide-loaded powder.

[0011] Step 2: Add a surfactant and absolute ethanol into liquid paraffin in a reaction kettle, ultrasonically disperse the astragalus polysaccharide-loaded powder in deionized water to obtain a dispersion liquid, then add the dispersion liquid into the reaction kettle with stirring at 35 - 40 °C, and then stir for 18 - 20 h to obtain the compound astragalus polysaccharide injection.

[0012] In the dispersion liquid, the dosage ratio of astragalus polysaccharide to deionized water is 1.8 - 2 g : 200 - 300 mL.

[0013] The surfactant is one or a mixture of two of Span60, Span80, Tween60, and Tween80.

[0014] Further, in Step 1, the dosage ratio of astragalus polysaccharide, deionized water, and composite nanoparticles is 6 - 8 g : 20 - 25 mL : 1.8 - 2 g.

[0015] Further, in Step 2, the dosage ratio of the surfactant, absolute ethanol, liquid paraffin, and the dispersion liquid is 30 - 35 g : 10 - 12 mL : 20 - 25 g : 20 - 30 g.

[0016] Further, the composite nanoparticles are prepared by the following steps:

[0017] Disperse poly(lactic acid) / nano-selenium microspheres in deionized water to prepare a 5 g / L poly(lactic acid) dispersion liquid. Add a cyclodextrin carrier and a polyvinyl alcohol surfactant into deionized water in a reaction kettle, add the poly(lactic acid) dispersion liquid into the reaction kettle, stir and react for 10 - 12 h, collect the precipitate after ultrafiltration to obtain the composite nanoparticles.

[0018] Further, the dosage ratio of the cyclodextrin carrier, polyvinyl alcohol surfactant, deionized water, and the poly(lactic acid) dispersion liquid is 1.5 - 2 g : 0.01 - 0.02 g : 80 - 100 mL : 150 - 200 mL.

[0019] Further, the cyclodextrin carrier is prepared by the following steps:

[0020] Dissolve potassium hydroxide and β-cyclodextrin in deionized water, add absolute ethanol, ultrasonicate and heat to 60 - 70 °C for reaction for 1 - 1.5 h, then add polyethylene glycol and react for 10 - 12 h. Centrifuge to collect the precipitate, wash it, and vacuum dry at 40 - 50 °C for 10 - 12 h to obtain the cyclodextrin carrier.

[0021] Furthermore, the dosage ratio of potassium hydroxide, β-cyclodextrin, deionized water, absolute ethanol, and polyethylene glycol is 1 - 1.5 g : 3 - 4 g : 10 - 15 mL : 60 - 80 mL : 1 - 1.5 g.

[0022] Furthermore, the poly(lactic acid) / nano-selenium microspheres are prepared by the following steps:

[0023] Dissolve poly(lactic acid) in acetone in a reaction kettle, add nano-selenium to the reaction kettle, stir for 20 - 30 min and then ultrasonicate in an ice bath for 15 - 20 min. Then add it to a polyvinyl alcohol solution with a concentration of 5 g / L and stir at 1000 - 1200 rpm for 10 - 12 h. Let it stand overnight and then centrifuge to collect the precipitate. Wash the precipitate with deionized water and then freeze-dry to obtain the poly(lactic acid) / nano-selenium microspheres.

[0024] Furthermore, the dosage ratio of poly(lactic acid), acetone, nano-selenium, and polyvinyl alcohol solution is 4 - 5 g : 100 - 150 mL : 0.5 - 0.7 g : 0.8 - 1 L.

[0025] The beneficial effects of the present invention are as follows: (1) The production process of the present invention adsorbs and encapsulates astragalus polysaccharide by preparing cyclodextrin into a carrier, and forms a core-shell structure with poly(lactic acid) by using the adsorption ability of the cyclodextrin carrier. The poly(lactic acid) coated with nano-selenium is loaded in the cyclodextrin carrier, which not only prevents the aggregation of nano-selenium in the injection solution, but also improves the dispersibility of astragalus polysaccharide. By preparing the composite nanoparticles into an emulsion, the dispersibility of the composite nanoparticles is improved. The injection solution in the form of an emulsion is more easily absorbed by animals, enabling nano-selenium and astragalus polysaccharide to produce a synergistic effect and improve the resistance of animals. (2) The veterinary compound astragalus polysaccharide injection solution prepared by the present invention is an emulsion with high dispersibility and good permeability. The composite nanoparticles in the emulsion improve the resistance of animals by compounding astragalus polysaccharide and nano-selenium, reduce the aggregation of nano-selenium by coating nano-selenium with poly(lactic acid), and form a core-shell structure by compounding the cyclodextrin carrier and poly(lactic acid) through the adsorption ability of the cyclodextrin carrier. Then, astragalus polysaccharide is impregnated and coated in the cyclodextrin carrier to improve the dispersibility of astragalus polysaccharide. Cyclodextrin and poly(lactic acid) are easily decomposed by animals, are non-toxic to animals, and have a good effect on improving the resistance of animals. Detailed implementation manners

[0026] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0027] Example 1: A production process of a veterinary compound astragalus polysaccharide injection, comprising the following steps:

[0028] S1. Dissolve 4 g of polylactic acid in 100 mL of acetone in a reaction kettle, add 0.5 g of nano-selenium to the reaction kettle, stir for 20 min and then perform ice bath ultrasonic treatment for 15 min, and then add it to 0.8 L of a polyvinyl alcohol solution with a concentration of 5 g / L and stir at 1000 rpm for 10 h. After standing overnight, centrifuge to collect the precipitate, wash the precipitate with deionized water and then freeze-dry to obtain polylactic acid / nano-selenium microspheres.

[0029] S2. Dissolve 1 g of potassium hydroxide and 3 g of β-cyclodextrin in 10 mL of deionized water, add 60 mL of absolute ethanol, perform ultrasonic treatment and heat to 60 °C for reaction for 1 h, then add 1 g of polyethylene glycol and react for 10 h. Centrifuge to collect the precipitate, wash it with absolute ethanol and then vacuum-dry at 40 °C for 10 h to obtain a cyclodextrin carrier.

[0030] S3. Disperse the polylactic acid / nano-selenium microspheres in deionized water to prepare a 5 g / L polylactic acid dispersion. In a reaction kettle, add 1.5 g of the cyclodextrin carrier and 0.01 g of a polyvinyl alcohol surfactant to 80 mL of deionized water, add 150 mL of the polylactic acid dispersion to the reaction kettle, stir and react for 10 h, and collect the precipitate after ultrafiltration to obtain composite nanoparticles.

[0031] S4. Dissolve 6 g of astragalus polysaccharide in 205 mL of deionized water in a reaction kettle, add 1.8 g of the composite nanoparticles to the reaction kettle, stir for 40 h, centrifuge to collect the precipitate, wash the precipitate with ethanol and then vacuum-dry at 40 °C for 10 h to obtain an astragalus polysaccharide-loaded powder.

[0032] S5. Add 30 g of Span60 and 10 mL of absolute ethanol to 20 g of liquid paraffin in a reaction kettle. Ultrasonically disperse 1.8 g of the astragalus polysaccharide-loaded powder in 200 mL of deionized water to obtain a dispersion, and then add 20 g of the dispersion to the reaction kettle while stirring at 35 °C, and then stir for 18 h to obtain a compound astragalus polysaccharide injection.

[0033] Example 2: A production process of a veterinary compound astragalus polysaccharide injection, comprising the following steps:

[0034] S1. Dissolve 4.5 g of polylactic acid in 125 mL of acetone in a reaction kettle. Add 0.6 g of nano-selenium to the reaction kettle. After stirring for 25 min, perform ice-bath ultrasonic treatment for 17 min. Then add it to 0.9 L of a polyvinyl alcohol solution with a concentration of 5 g / L and stir at 1100 rpm for 11 h. Let it stand overnight and then centrifuge to collect the precipitate. Wash the precipitate with deionized water and then freeze-dry to obtain polylactic acid / nano-selenium microspheres.

[0035] S2. Dissolve 1.25 g of potassium hydroxide and 3.5 g of β-cyclodextrin in 12.5 mL of deionized water. Add 70 mL of absolute ethanol, perform ultrasonic treatment and heat to 65 °C for reaction for 1.25 h. Then add 1.25 g of polyethylene glycol and react for 11 h. Centrifuge to collect the precipitate, wash it with absolute ethanol and then vacuum-dry at 45 °C for 11 h to obtain the cyclodextrin carrier.

[0036] S3. Disperse the polylactic acid / nano-selenium microspheres in deionized water to prepare a 5 g / L polylactic acid dispersion. In a reaction kettle, add 1.75 g of the cyclodextrin carrier and 0.015 g of polyvinyl alcohol surfactant to 90 mL of deionized water. Add 175 mL of the polylactic acid dispersion to the reaction kettle and stir for reaction for 11 h. After ultrafiltration, collect the precipitate to obtain the composite nanoparticles.

[0037] S4. Dissolve 7 g of astragalus polysaccharide in 22.5 mL of deionized water in a reaction kettle. Add 1.9 g of the composite nanoparticles to the reaction kettle, stir for 44 h, centrifuge to collect the precipitate, wash the precipitate with ethanol and then vacuum-dry at 45 °C for 11 h to obtain the astragalus polysaccharide-loaded powder.

[0038] S5. Add 10 g of Span60, 22.5 g of Span80 and 11 mL of absolute ethanol to 22.5 g of liquid paraffin in a reaction kettle. Ultrasonically disperse 1.9 g of the astragalus polysaccharide-loaded powder in 250 mL of deionized water to obtain a dispersion. Then add 25 g of the dispersion to the reaction kettle with stirring at 37 °C. Then stir for 19 h to obtain the compound astragalus polysaccharide injection.

[0039] Example 3: A production process of a veterinary compound astragalus polysaccharide injection, including the following steps:

[0040] S1. Dissolve 5 g of polylactic acid in 150 mL of acetone in a reaction kettle. Add 0.7 g of nano-selenium to the reaction kettle. After stirring for 30 min, perform ice-bath ultrasonic treatment for 20 min. Then add it to 1 L of a polyvinyl alcohol solution with a concentration of 5 g / L and stir at 1200 rpm for 12 h. Let it stand overnight and then centrifuge to collect the precipitate. Wash the precipitate with deionized water and then freeze-dry to obtain polylactic acid / nano-selenium microspheres.

[0041] S2. Dissolve 1.5 g of potassium hydroxide and 4 g of β-cyclodextrin in 15 mL of deionized water, add 80 mL of absolute ethanol, ultrasonicate and heat to 70 °C for reaction for 1.5 h, then add 1.5 g of polyethylene glycol and react for 12 h. Centrifuge to collect the precipitate, wash it with absolute ethanol and then dry it under vacuum at 50 °C for 12 h to obtain the cyclodextrin carrier.

[0042] The cyclodextrin carrier is prepared by binding cyclodextrin as an organic ligand with potassium ions through coordination bonds. It has adsorption ability and encapsulation ability, and is safe, non-toxic and can be degraded by animals.

[0043] S3. Disperse the polylactic acid / nano-selenium microspheres in deionized water to prepare a 5 g / L polylactic acid dispersion. In a reaction kettle, add 2 g of cyclodextrin carrier and 0.02 g of polyvinyl alcohol surfactant to 100 mL of deionized water, add 200 mL of polylactic acid dispersion to the reaction kettle, stir and react for 12 h, ultrafilter and then collect the precipitate to obtain the composite nanoparticles.

[0044] Under the action of polyvinyl alcohol surfactant, the cyclodextrin carrier is adsorbed on the polylactic acid / nano-selenium microspheres to form composite nanoparticles with the polylactic acid / nano-selenium microspheres as the core and the cyclodextrin carrier as the shell, separating the nano-selenium and reducing the aggregation of nano-selenium. Polylactic acid and cyclodextrin are safe, non-toxic and can be degraded and metabolized by animals. Nano-selenium can provide selenium element for animals, promote the growth of animals and improve the resistance of animals.

[0045] S4. Dissolve 8 g of astragalus polysaccharide in 25 mL of deionized water in a reaction kettle, add 2 g of composite nanoparticles to the reaction kettle, stir for 48 h, centrifuge to collect the precipitate, wash the precipitate with ethanol and then dry it under vacuum at 50 °C for 12 h to obtain the astragalus polysaccharide-loaded powder.

[0046] By the impregnation method, using the adsorption ability of the cyclodextrin carrier in the composite nanoparticles, the astragalus polysaccharide is adsorbed and encapsulated on the surface of the cyclodextrin carrier, reducing the precipitation of astragalus polysaccharide caused by long-term standing. The combined action of astragalus polysaccharide and nano-selenium can improve the resistance of animals.

[0047] S5. Add 10 g of Tween 80, 25 g of Tween 60 and 12 mL of absolute ethanol to 25 g of liquid paraffin in a reaction kettle. Ultrasonically disperse 2 g of astragalus polysaccharide-loaded powder in 300 mL of deionized water to obtain a dispersion, then add 30 g of the dispersion to the reaction kettle with stirring at 40 °C, and then stir for 20 h to obtain the compound astragalus polysaccharide injection.

[0048] After dispersing the astragalus polysaccharide-loaded powder in water, a nanoemulsion is formed with liquid paraffin under the action of a surfactant. The nanoemulsion has high stability, is convenient for transportation and storage, has high dispersibility and good permeability after injection, and has a good synergistic effect with nano-selenium, showing good improvement in the resistance of animals.

[0049] Comparative Example 1: The difference from Example 1 is that nano-selenium is used to replace the poly(lactic acid) / nano-selenium microspheres to prepare a compound astragalus polysaccharide injection.

[0050] Comparative Example 2: The difference from Example 1 is that a cyclodextrin carrier is used to replace the composite nanoparticles to prepare a compound astragalus polysaccharide injection.

[0051] Comparative Example 3: The difference from Example 1 is that a cyclodextrin carrier is used to replace the composite nanoparticles to prepare an astragalus polysaccharide cyclodextrin carrier, and the above astragalus polysaccharide cyclodextrin carrier and poly(lactic acid) nano-selenium microspheres are used to replace the astragalus polysaccharide-loaded powder.

[0052] Performance tests were carried out on the compound astragalus polysaccharide injections prepared in Examples 1 - 3 and Comparative Examples 1 - 3. A total of 120 piglets at the 40-day-old nursery stage were randomly selected and divided into 6 groups with 20 piglets in each group. The compound astragalus polysaccharide injection was intramuscularly injected at a dose of 0.2 mL per kilogram of body weight once a week for 3 consecutive weeks. In the fourth week, 5 mL of blood was collected from each piglet in the six groups, including 2.5 mL of whole blood and 2.5 mL used to prepare serum. The activity of superoxide dismutase (SOD) was measured, the immunoglobulin of pigs was measured by immunoturbidimetry, and the red blood cell count was measured by the tube dilution method. The results were averaged.

[0053] The results are shown in Table 1:

[0054] Project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Immunoglobulin (g / L) 136.35 139.72 141.49 114.21 120.56 126.17 <![CDATA[Red blood cell count (10 9 / L)]]> 11.89 12.13 12.41 9.17 10.22 10.76 SOD (U / mL) 168.24 173.26 176.05 145.38 152.16 159.54

[0055] As shown in Table 1, the compound astragalus polysaccharide injection prepared by the present invention significantly improves the immunoglobulin and red blood cell count of piglets, and has a high SOD activity, indicating that the compound astragalus polysaccharide injection prepared by the present invention has a good effect on improving the immunity of piglets.

[0056] In Comparative Example 1, since nano-selenium is directly compounded with the cyclodextrin carrier, nano-selenium is deposited in the pores of the cyclodextrin carrier, reducing the loading amount of the cyclodextrin carrier for astragalus polysaccharide, and the improvement of the immune ability of piglets is poor.

[0057] In Comparative Example 2, since the poly(lactic acid) / nano-selenium microspheres are not added and there is no synergistic effect of nano-selenium, the improvement of the immune ability of piglets is worse than that of Examples 1 - 3 and Comparative Example 3.

[0058] In Comparative Example 3, since astragalus polysaccharide was loaded on a cyclodextrin carrier and then added to the oil phase separately from the polylactic acid / nano-selenium microspheres to prepare an emulsion, the dispersibility of nano-selenium and astragalus polysaccharide was different, and the synergistic effect was small, resulting in a poorer improvement in the immune ability of piglets than that in Examples 1 to 3.

[0059] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A production process of a compound astragalus polysaccharide injection for veterinary use, characterized in that, It includes the following steps: S1. Dissolve polylactic acid in acetone in a reaction kettle, add nano-selenium into the reaction kettle, stir for 20 - 30 min, then perform ice bath ultrasonic treatment for 15 - 20 min, and then add it into a polyvinyl alcohol solution with a concentration of 5 g / L and stir at 1000 - 1200 rpm for 10 - 12 h. Let it stand overnight and then centrifuge to collect the precipitate. Wash the precipitate with deionized water and then freeze-dry to obtain polylactic acid / nano-selenium microspheres; S2. Dissolve potassium hydroxide and β-cyclodextrin in deionized water, add absolute ethanol, perform ultrasonic treatment and heat to 60 - 70 °C for reaction for 1 - 1.5 h, then add polyethylene glycol and react for 10 - 12 h. Centrifuge to collect the precipitate, wash it, and vacuum dry at 40 - 50 °C for 10 - 12 h to obtain a cyclodextrin carrier; S3. Disperse the polylactic acid / nano-selenium microspheres in deionized water to prepare a 5 g / L polylactic acid dispersion. Add the cyclodextrin carrier and polyvinyl alcohol surfactant into deionized water in a reaction kettle, add the polylactic acid dispersion into the reaction kettle, stir and react for 10 - 12 h, collect the precipitate after ultrafiltration to obtain composite nanoparticles; S4. Dissolve astragalus polysaccharide in deionized water in a reaction kettle, add the composite nanoparticles into the reaction kettle, stir for 40 - 48 h, centrifuge to collect the precipitate, wash the precipitate with ethanol and then vacuum dry at 40 - 50 °C for 10 - 12 h to obtain astragalus polysaccharide-loaded powder; S5. Add a surfactant and absolute ethanol into liquid paraffin in a reaction kettle. Ultrasonically disperse the astragalus polysaccharide-loaded powder in deionized water to obtain a dispersion, and then add the dispersion into the reaction kettle while stirring at 35 - 40 °C, and then stir for 18 - 20 h to obtain compound astragalus polysaccharide injection; In the dispersion of S5, the dosage ratio of the astragalus polysaccharide-loaded powder to deionized water is 1.8 - 2 g : 200 - 300 mL; The surfactant in S5 is one or a mixture of two of Span60, Span80, Tween60, and Tween80.

2. The production process of a veterinary compound astragalus polysaccharide injection according to claim 1, characterized in that, In S4, the dosage ratio of the astragalus polysaccharide, deionized water, and the composite nanoparticles is 6 - 8 g : 20 - 25 mL : 1.8 - 2 g.

3. The production process of a veterinary compound astragalus polysaccharide injection according to claim 1, characterized in that, In S5, the dosage ratio of the surfactant, absolute ethanol, liquid paraffin, and the dispersion is 30 - 35 g : 10 - 12 mL : 20 - 25 g : 20 - 30 g.

4. The production process of a veterinary compound astragalus polysaccharide injection according to claim 1, characterized in that, The dosage ratio of the cyclodextrin carrier, polyvinyl alcohol surfactant, deionized water, and the polylactic acid dispersion is 1.5 - 2 g : 0.01 - 0.02 g : 80 - 100 mL : 150 - 200 mL.

5. The production process of a veterinary compound astragalus polysaccharide injection according to claim 1, characterized in that, The dosage ratio of potassium hydroxide, β-cyclodextrin, deionized water, absolute ethanol, and polyethylene glycol is 1 - 1.5 g : 3 - 4 g : 10 - 15 mL : 60 - 80 mL : 1 - 1.5 g.

6. The production process of a veterinary compound astragalus polysaccharide injection according to claim 1, characterized in that, The dosage ratio of polylactic acid, acetone, nano-selenium, and the polyvinyl alcohol solution is 4 - 5 g : 100 - 150 mL : 0.5 - 0.7 g : 0.8 - 1 L.

7. A compound astragalus polysaccharide injection for veterinary use, characterized in that, It is prepared by the production process described in any one of claims 1 - 6.