Erythromycin enteric-coated preparation and preparation method thereof

Abstract

The invention discloses an erythromycin enteric-coated preparation and a preparation method thereof, and relates to the technical field of medicines. The erythromycin enteric-coated preparation comprises a plain pill and a water-soluble coating material, and the plain pill is prepared from the following raw materials in parts by weight: 125 parts of erythromycin, 35 parts of lactose monohydrate, 5 parts of povidone K90, 5 parts of monopotassium phosphate and 34-47.6 parts of purified water. According to the preparation method, K90 is taken as a raw material, after K90 is added, the erythromycin pellets have good forming degree during extrusion forming, the situation that the viscosity is too high does not exist, the obtained pellets are uniform in particle size and appropriate in size, and when the product is prepared, the sieving step can be omitted, the preparation steps can be reduced, and the production cost can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of medicines, and in particular to an erythromycin enteric-coated preparation and a preparation method thereof. Background Art

[0002] Erythromycin is a representative antibiotic of the macrolide family produced by Streptomyces erythromycin. It is mainly used clinically for penicillin-resistant Staphylococcus aureus infections and penicillin-allergic Staphylococcus aureus infections. It is also used for respiratory tract infections, Legionella pneumonia, mycoplasma pneumonia, skin and soft tissue infections caused by hemolytic streptococci and pneumococci.

[0003] There are many dosage forms of erythromycin, among which erythromycin enteric-coated capsules are a more common dosage form, which will not be damaged in gastric juice, and will not be decomposed and absorbed until in the intestinal juice, so it can reduce the damage and stimulation of erythromycin to the gastric mucosa. Erythromycin enteric-coated capsules are currently listed in the domestic reference preparation catalog. The fifth batch and the eightieth batch of reference preparation catalogs are published. The reference preparation of this product is MaynePharma International Pty Ltd / DR REDDYS LABORATORIES SA, and the specification is 0.25g (250,000 units). From the instructions, patent information and samples of the reference preparations listed in the United States, it can be known that erythromycin enteric-coated capsules adopt the following process: wet granulation, extrusion spheronization granulation to obtain plain pills, a layer of enteric coating is wrapped on the plain pills, and finally capsules are filled.

[0004] In the prior art, the enteric coating material of the reference preparation of this product adopts the method of cellulose acetate (CAP) + diethyl phthalate (plasticizer). From the solubility analysis of the above two, the enteric material CAP and its plasticizer are not soluble in water, and have good solubility in acetone and ethanol mixed solvents. Existing data show that it is prepared by organic solvent coating. However, organic solvent coating is limited by environmental, explosion-proof, sanitation, health and other factors; and the residual organic solvent will cause safety risks to this product, requiring the production workshop to have an explosion-proof process, which increases the production cost.

[0005] After reverse analysis of the reference preparation, the results of erythromycin enteric-coated capsules showed that the weight of the coated pills was about 390 mg, while the API accounted for 250 mg (about 64%), the weight of the pills was about 330 mg, and the API was 250 mg, accounting for 76%. The reference preparation pills only contained API, lactose monohydrate, polyvinyl pyrrolidone (PVP), and potassium dihydrogen phosphate. In order to ensure that the dissolution of the preparation is consistent with the reference preparation, the particle size of the erythromycin API needs to be controlled at D90≤10μm. Combined with the actual situation that the API accounts for a high proportion, the extrusion and spheronization processes in the preparation of the pills of this product face great challenges, mainly due to the difficulty of extrusion and spheronization. Summary of the invention

[0006] The technical problem to be solved by the present invention is that the existing erythromycin enteric-coated preparation has the problems of difficulty in extrusion, difficulty in rounding and high production cost. The purpose is to provide an erythromycin enteric-coated preparation and a preparation method thereof, which solves the problems of difficulty in extrusion, difficulty in rounding and high production cost.

[0007] The present invention is achieved through the following technical solutions:

[0008] An erythromycin enteric-coated preparation comprises a raw material of a vegetarian pill and a water-soluble coating material, wherein the raw material of the raw material of the vegetarian pill is as follows in parts by weight:

[0009] 125 parts of erythromycin, 35 parts of lactose monohydrate, 5 parts of povidone K90, 5 parts of potassium dihydrogen phosphate and 34-47.6 parts of purified water.

[0010] As a possible design, the above-mentioned erythromycin enteric-coated preparation comprises the following raw materials in parts by weight:

[0011] 125 parts of erythromycin, 35 parts of lactose monohydrate, 5 parts of povidone K90, 5 parts of potassium dihydrogen phosphate and 42.5 parts of purified water.

[0012] As a possible design, the water-soluble coating material accounts for 20% of the weight of the erythromycin enteric-coated preparation.

[0013] As a possible design, the water-soluble coating material includes methacrylic acid-ethyl acrylate copolymer aqueous dispersion (L30D-55).

[0014] A method for preparing an erythromycin enteric-coated preparation comprises the following steps:

[0015] Weigh erythromycin, lactose monohydrate, povidone K90, potassium dihydrogen phosphate, purified water and water-soluble coating materials;

[0016] Dissolve povidone K90 and potassium dihydrogen phosphate in purified water to prepare a granulation solution;

[0017] Mixing erythromycin and lactose monohydrate, performing wet granulation using a granulation solution after mixing evenly, extruding, spheronizing and drying to obtain erythromycin pills;

[0018] dissolving a water-soluble coating material in water to obtain a coating solution;

[0019] The erythromycin pills are coated with the coating liquid, dried, and filled into capsules to obtain the erythromycin enteric-coated preparation.

[0020] As a possible design, the concentration of the water-soluble coating material in the above coating solution is 15%.

[0021] As a possible design, the particle size of the erythromycin pellets is less than 1.7 mm.

[0022] As a possible design, the water content of the erythromycin pills is less than 5%.

[0023] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0024] The present invention uses K90 as a raw material. After adding K90, the erythromycin pills have good molding degree during extrusion molding, and there is no situation of excessive viscosity. The obtained pellets have uniform particles and appropriate sizes, so that when preparing the product, the screening step can be omitted, the preparation steps are reduced, and the production cost is reduced.

[0025] During the preparation of the present invention, the vegetarian pills are wrapped with a water-soluble coating material, and there is no need to use explosive organic solvents, so there is no need to carry out explosion-proof transformation of the production workshop, the safety of the medicine is improved, the preparation cost is reduced, and the preparation process is environmentally friendly, safe and hygienic.

[0026] In addition, the erythromycin enteric-coated formulation of the present invention has a good enteric-coated effect, does not require the use of disintegrants, etc., reduces the complexity of raw materials and auxiliary materials, and reduces process steps (adding a disintegrant requires an additional step of mixing). Adding a disintegrant will increase the difficulty and cost of product quality control, and the quality risk of a product without adding a disintegrant is lower and the quality is more controllable; the results of dissolution using an existing prescription show that the dissolution effect is good (the dissolution rate in a pH 6.8 dissolution medium is greater than 85% in 60 minutes). BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without creative work. In the drawings:

[0028] Figure 1 The dissolution curves of Example 2 and Comparative Examples 4 to 6 in Experimental Example 1 of the present invention are shown;

[0029] Figure 2 This is a product picture of comparative example 3 in experimental example 1 of the present invention;

[0030] Figure 3 This is a product picture of Example 2 in Experimental Example 1 of the present invention. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with examples and drawings. The illustrative embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention. If specific conditions are not specified in the examples, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0032] During the preparation of existing erythromycin enteric-coated preparations, organic solvents (such as acetone and ethanol) are required to dissolve the coating materials. However, organic solvent coating is limited by environmental, explosion-proof, hygienic, and health factors. Moreover, the residual organic solvent may cause safety risks to the product. In addition, the existing erythromycin enteric-coated pellets are difficult to extrude and have poor molding degree during the extrusion molding step, and it is not easy to obtain round and uniform pellets. If the roundness of the pellets is poor, the release rate and degree of the erythromycin enteric-coated preparations will be affected, which is the key to ensuring bioequivalence.

[0033] Based on the above reasons, the inventors chose K90 as a binder. After research by the inventors, it was found that the selection of K90 can improve the molding degree and sphericity of the plain pills, and can ensure that rounded pellets are obtained, so that the release rate and degree of the erythromycin enteric-coated preparation are close to those of the original drug, and the consistency of the dissolution behavior is ensured. In addition, the water-soluble coating material is selected as the raw material, which reduces the complexity of the preparation and the explosion-proof requirements for the preparation workshop while ensuring that the drug absorption effect and release rate are not changed, and is environmentally friendly and safe.

[0034] In a first aspect, the present invention provides an erythromycin enteric-coated preparation, comprising a raw material of a pellet and a water-soluble coating material, wherein the raw material of the raw material of the pellet is as follows in parts by weight:

[0035] 125 parts of erythromycin, 35 parts of lactose monohydrate, 5 parts of povidone K90, 5 parts of potassium dihydrogen phosphate and 34-47.6 parts of purified water.

[0036] In some embodiments of the present invention, the above-mentioned erythromycin enteric-coated preparation comprises the following raw materials in parts by weight:

[0037] 125 parts of erythromycin, 35 parts of lactose monohydrate, 5 parts of povidone K90, 5 parts of potassium dihydrogen phosphate and 42.5 parts of purified water.

[0038] In some embodiments of the present invention, the water-soluble coating material is 20% of the weight of the erythromycin enteric-coated preparation. The sample prepared under this ratio has good acid resistance and a 60-min solubility of greater than 85% in a pH 6.8 dissolution medium.

[0039] In some embodiments of the present invention, the water-soluble coating material includes methacrylic acid-ethyl acrylate copolymer aqueous dispersion L30D-55.

[0040] In a second aspect, the present invention provides a method for preparing an erythromycin enteric-coated preparation, comprising the following steps:

[0041] Weigh erythromycin, lactose monohydrate, povidone K90, potassium dihydrogen phosphate, purified water and water-soluble coating materials;

[0042] Dissolve povidone K90 and potassium dihydrogen phosphate in purified water to prepare a granulation solution;

[0043] Mixing erythromycin and lactose monohydrate, performing wet granulation using a granulation solution after mixing evenly, extruding, spheronizing and drying to obtain erythromycin pills;

[0044] dissolving a water-soluble coating material in water to obtain a coating solution;

[0045] The erythromycin pills are coated with the coating liquid, dried, and filled into capsules to obtain the erythromycin enteric-coated preparation.

[0046] Preferably, the moisture content of the erythromycin pills is less than 5%.

[0047] Preferably, the temperature of the granulation solution is 60°C, and the wet granulation parameters are as follows: stirring speed 200rpm, chopping speed 600rpm, atomization pressure 0.05MPa, granulation solution pump speed 5ml / min; the feeding speed of the extrusion treatment is 50rpm, the extrusion speed is 50rpm; the spheronization speed of the spheronization treatment is 900rpm, and the spheronization time is 10min; drying is drying at 40°C for 2h; the coating treatment parameters are as follows: material temperature 24-28°C, air inlet temperature 35°C, fan speed 500rpm, atomization pressure 0.15mPa, coating liquid pump speed 2.0rpm.

[0048] In some embodiments of the present invention, the concentration of the water-soluble coating material in the coating solution is 15%, which is beneficial to improve the coating uniformity and prevent the particles from sticking during the coating process.

[0049] In some embodiments of the present invention, the particle size of the erythromycin pellets is less than 1.7 mm.

[0050] In some embodiments of the present invention, the water content of the erythromycin pills is less than 5%.

[0051] Example 1

[0052] A method for preparing an erythromycin enteric-coated preparation comprises the following steps:

[0053] Weigh the raw materials:

[0054] Erythromycin 125 g, lactose monohydrate 35 g, povidone K90 5 g, potassium dihydrogen phosphate 5 g, purified water 34 g and water-soluble coating material (L30D-55);

[0055] Dissolve povidone K90 and potassium dihydrogen phosphate in purified water to prepare a granulation solution;

[0056] Mix erythromycin and lactose monohydrate, mix well, perform wet granulation with a granulation solution, extrude, spheronize and dry to obtain erythromycin pills (water content less than 5%);

[0057] Dissolving the water-soluble coating material L30D-55 in water to obtain a coating solution;

[0058] The erythromycin pills are coated with the coating liquid, dried, and filled into capsules to obtain the erythromycin enteric-coated preparation.

[0059] Example 2

[0060] This embodiment is basically the same as embodiment 1, except that the amount of purified water used is 42.5 g.

[0061] A method for preparing an erythromycin enteric-coated preparation comprises the following steps:

[0062] Weigh the raw materials:

[0063] Erythromycin 125 g, lactose monohydrate 35 g, povidone K90 5 g, potassium dihydrogen phosphate 5 g, purified water 42.5 g and water-soluble coating material (L30D-55);

[0064] Dissolve povidone K90 and potassium dihydrogen phosphate in purified water to prepare a granulation solution;

[0065] Mix erythromycin and lactose monohydrate, mix well, perform wet granulation with a granulation solution, extrude, spheronize and dry to obtain erythromycin pills (water content less than 5%);

[0066] Dissolving the water-soluble coating material L30D-55 in water to obtain a coating solution;

[0067] The erythromycin pills are coated with the coating liquid, dried, and filled into capsules to obtain the erythromycin enteric-coated preparation.

[0068] Example 3

[0069] This embodiment is basically the same as embodiment 1, except that the amount of purified water used is 47.6 g.

[0070] A method for preparing an erythromycin enteric-coated preparation comprises the following steps:

[0071] Weigh the raw materials:

[0072] Erythromycin 125 g, lactose monohydrate 35 g, povidone K90 5 g, potassium dihydrogen phosphate 5 g, purified water 47.6 g and water-soluble coating material (L30D-55);

[0073] Dissolve povidone K90 and potassium dihydrogen phosphate in purified water to prepare a granulation solution;

[0074] Mix erythromycin and lactose monohydrate, mix well, perform wet granulation with a granulation solution, extrude, spheronize and dry to obtain erythromycin pills (water content less than 5%);

[0075] Dissolving the water-soluble coating material L30D-55 in water to obtain a coating solution;

[0076] The erythromycin pills are coated with the coating liquid, dried, and filled into capsules to obtain the erythromycin enteric-coated preparation.

[0077] Comparative Example 1

[0078] This comparative example is substantially the same as Example 2, except that the amount of purified water used is 30.6 g.

[0079] A method for preparing an erythromycin enteric-coated preparation comprises the following steps:

[0080] Weigh the raw materials:

[0081] Erythromycin 125 g, lactose monohydrate 35 g, povidone K90 5 g, potassium dihydrogen phosphate 5 g, purified water 30.6 g and water-soluble coating material (L30D-55);

[0082] Dissolve povidone K90 and potassium dihydrogen phosphate in purified water to prepare a granulation solution;

[0083] Mix erythromycin and lactose monohydrate, mix well, perform wet granulation with a granulation solution, extrude, spheronize and dry to obtain erythromycin pills (water content less than 5%);

[0084] Dissolving the water-soluble coating material L30D-55 in water to obtain a coating solution;

[0085] The erythromycin pills are coated with the coating liquid, dried, and filled into capsules to obtain the erythromycin enteric-coated preparation.

[0086] Comparative Example 2

[0087] This comparative example is substantially the same as Example 2, except that the amount of purified water used is 47.6 g.

[0088] A method for preparing an erythromycin enteric-coated preparation comprises the following steps:

[0089] Weigh the raw materials:

[0090] Erythromycin 125 g, lactose monohydrate 35 g, povidone K90 5 g, potassium dihydrogen phosphate 5 g, purified water 47.6 g and water-soluble coating material (L30D-55);

[0091] Dissolve povidone K90 and potassium dihydrogen phosphate in purified water to prepare a granulation solution;

[0092] Mix erythromycin and lactose monohydrate, mix well, perform wet granulation with a granulation solution, extrude, spheronize and dry to obtain erythromycin pills (water content less than 5%);

[0093] Dissolving the water-soluble coating material L30D-55 in water to obtain a coating solution;

[0094] The erythromycin pills are coated with the coating liquid, dried, and filled into capsules to obtain the erythromycin enteric-coated preparation.

[0095] Comparative Example 3

[0096] This comparative example is substantially the same as Example 2, except that povidone K90 is replaced by povidone K30.

[0097] A method for preparing an erythromycin enteric-coated preparation comprises the following steps:

[0098] Weigh the raw materials:

[0099] Erythromycin 125 g, lactose monohydrate 35 g, povidone k30 5 g, potassium dihydrogen phosphate 5 g, purified water 42.5 g and water-soluble coating material (L30D-55);

[0100] Dissolve povidone K30 and potassium dihydrogen phosphate in purified water to prepare a granulation solution;

[0101] Mix erythromycin and lactose monohydrate, mix well, perform wet granulation with a granulation solution, extrude, spheronize and dry to obtain erythromycin pills (water content less than 5%);

[0102] Dissolving the water-soluble coating material L30D-55 in water to obtain a coating solution;

[0103] The erythromycin pills are coated with the coating liquid, dried, and filled into capsules to obtain the erythromycin enteric-coated preparation.

[0104] Comparative Example 4

[0105] This comparative example is the reference preparation described in the background technology, which is basically the same as Example 2, except that the water-soluble coating material (L30D-55) is replaced with cellulose acetate phthalate (CAP) with a concentration of 10%, and is dissolved in a mixed solvent of acetone:ethanol = 1:1.

[0106] A method for preparing an erythromycin enteric-coated preparation comprises the following steps:

[0107] Weigh the raw materials:

[0108] Erythromycin 125 g, lactose monohydrate 35 g, povidone K90 5 g, potassium dihydrogen phosphate 5 g, purified water 42.5 g and coating material (CAP);

[0109] Dissolve povidone K90 and potassium dihydrogen phosphate in purified water to prepare a granulation solution;

[0110] Mix erythromycin and lactose monohydrate, mix well, perform wet granulation with a granulation solution, extrude, spheronize and dry to obtain erythromycin pills (water content less than 5%);

[0111] The coating material CAP was dissolved in a mixed solvent (acetone: ethanol = 1:1) to obtain a coating solution;

[0112] The erythromycin pills are coated with the coating liquid, dried, and filled into capsules to obtain the erythromycin enteric-coated preparation.

[0113] Comparative Example 5

[0114] This comparative example is basically the same as Example 2, except that the water-soluble coating material (L30D-55) is replaced by hydroxypropyl methylcellulose phthalate (HPMCP), and since the enteric material is easily soluble in alkaline solution, ammonia water is used to adjust the pH of purified water to alkaline.

[0115] A method for preparing an erythromycin enteric-coated preparation comprises the following steps:

[0116] Weigh the raw materials:

[0117] Erythromycin 125 g, lactose monohydrate 35 g, povidone K90 5 g, potassium dihydrogen phosphate 5 g, purified water 42.5 g and water-soluble coating material (HPMCP);

[0118] Dissolve povidone K90 and potassium dihydrogen phosphate in purified water to prepare a granulation solution;

[0119] Mix erythromycin and lactose monohydrate, mix well, perform wet granulation with a granulation solution, extrude, spheronize and dry to obtain erythromycin pills (water content less than 5%);

[0120] The pH of purified water is adjusted to alkaline using aqueous ammonia, and the water-soluble coating material HPMCP is dissolved in water to obtain a coating solution;

[0121] The erythromycin pills are coated with the coating liquid, dried, and filled into capsules to obtain the erythromycin enteric-coated preparation.

[0122] Comparative Example 6

[0123] This comparative example is basically the same as Example 2, except that the water-soluble coating material (L30D-55) is replaced by hydroxypropyl methylcellulose phthalate (CAP), and since the enteric material is easily soluble in alkaline solution, ammonia water is used to adjust the pH of purified water to alkaline.

[0124] A method for preparing an erythromycin enteric-coated preparation comprises the following steps:

[0125] Weigh the raw materials:

[0126] Erythromycin 125 g, lactose monohydrate 35 g, povidone K90 5 g, potassium dihydrogen phosphate 5 g, purified water 42.5 g and coating material (CAP);

[0127] Dissolve povidone K90 and potassium dihydrogen phosphate in purified water to prepare a granulation solution;

[0128] Mix erythromycin and lactose monohydrate, mix well, perform wet granulation with a granulation solution, extrude, spheronize and dry to obtain erythromycin pills (water content less than 5%);

[0129] The pH of purified water is adjusted to alkaline using aqueous ammonia, and the water-soluble coating material CAP is dissolved in water to obtain a coating solution;

[0130] The erythromycin pills are coated with the coating liquid, dried, and filled into capsules to obtain the erythromycin enteric-coated preparation.

[0131] Experimental Example 1

[0132] (1) The pellets of Examples 1 to 3 and Comparative Examples 1 to 2 were extruded and rounded. The results are shown in Table 1.

[0133] Table 1

[0134]

[0135] From Table 1, it can be seen that the samples extruded from Examples 1 to 3 are in strips, and the particles have good roundness during spheronization. In Comparative Example 1, where less water is added, the sample extruded is in powder form and cannot be formed, resulting in poor subsequent spheronization effect and affecting subsequent absorption. In Comparative Example 2, where more water is added, the sample extruded is not easy to break, resulting in serious adhesion of the particles during subsequent spheronization, and no uniform pellets can be obtained.

[0136] (2) Observe the roundness of the balls of Example 2 and Comparative Example 3. The results are shown in Table 2 and Figures 2-3 shown.

[0137] Table 2

[0138]

[0139]

[0140] Observe Table 2 and Figures 2-3 It can be seen that after replacing K90 with K30, the roundness of the pellets is poor. Generally speaking, the greater the viscosity of the adhesive used, the easier it is for the material to adhere and form larger lumps, which is not conducive to the formation of uniform, rounded particles to a certain extent, resulting in pellets of different sizes and even forming lumps, rather than ideal rounded particles. K90 and K30 are both polyvinyl pyrrolidone, the difference being that K90 has a larger molecular weight. Generally speaking, the higher the molecular weight of polyvinyl pyrrolidone, the greater the viscosity. However, in the present invention, the rounding effect of the pellets obtained using K90 as a binder is much higher than that of the pellets obtained using K30 as a binder.

[0141] (3) pH 6.8 phosphate buffer dissolution test was conducted on the erythromycin enteric-coated preparations of Example 2 and Comparative Examples 4 to 6. The results are shown in Tables 3 and Figure 1 As shown, the horizontal axis of the figure is the dissolution time (min), and the vertical axis is the dissolution rate (%).

[0142] Table 3

[0143]

[0144] By comparing Example 2 and Comparative Example 4, it can be seen that the release behavior of the preparation of Example 2 is close to that of the reference preparation (Comparative Example 4), and the overall release behavior is better than that of the reference preparation (cumulative release), and the limitation of the use of organic solvents in the product is also solved.

[0145] Comparing Examples 2 and 5-6, it can be seen that although Examples 5-6 are also water-soluble, the release effect is obviously worse than that of Example 2, and the release rate is also lower than that of Example 2.

[0146] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An erythromycin enteric-coated preparation, characterized in that: It comprises vegetarian pills and water-soluble coating materials, wherein the vegetarian pills have the following raw materials in parts by weight: 125 parts of erythromycin, 35 parts of lactose monohydrate, 5 parts of povidone K90, 5 parts of potassium dihydrogen phosphate and 34-47.6 parts of purified water.

2. An erythromycin enteric-coated preparation according to claim 1, characterized in that: The erythromycin enteric-coated preparation comprises the following raw materials in parts by weight: 125 parts of erythromycin, 35 parts of lactose monohydrate, 5 parts of povidone K90, 5 parts of potassium dihydrogen phosphate and 42.5 parts of purified water.

3. An erythromycin enteric-coated preparation according to claim 1, characterized in that: The water-soluble coating material accounts for 20% of the weight of the erythromycin enteric-coated preparation.

4. An erythromycin enteric-coated preparation according to claim 1, characterized in that: The water-soluble coating material includes L30D-55.

5. The method for preparing an erythromycin enteric-coated preparation according to any one of claims 1 to 4, characterized in that: The steps include: Weigh erythromycin, lactose monohydrate, povidone K90, potassium dihydrogen phosphate, purified water and water-soluble coating materials; Dissolve povidone K90 and potassium dihydrogen phosphate in purified water to prepare a granulation solution; Mixing erythromycin and lactose monohydrate, performing wet granulation using a granulation solution after mixing evenly, extruding, spheronizing and drying to obtain erythromycin pills; dissolving a water-soluble coating material in water to obtain a coating solution; The erythromycin pills are coated with the coating liquid, dried, and filled into capsules to obtain the erythromycin enteric-coated preparation.

6. The method for preparing an erythromycin enteric-coated preparation according to claim 5, characterized in that: The concentration of the water-soluble coating material in the coating solution is 15%.

7. The method for preparing an erythromycin enteric-coated preparation according to claim 5, characterized in that: The particle size of the erythromycin pills is less than 1.7 mm.

8. The method for preparing an erythromycin enteric-coated preparation according to claim 5, characterized in that: The water content of the erythromycin pills is less than 5%.

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