Veterinary sodium dichloroisocyanurate effervescent tablet with high stability and preparation method of veterinary sodium dichloroisocyanurate effervescent tablet

Abstract

The invention relates to a high-stability sodium dichloroisocyanurate effervescent tablet for veterinary use. The effervescent tablet is mainly prepared from the following raw materials in percentage by weight: 40 to 50 percent of microencapsulated sodium dichloroisocyanurate, 25 to 30 percent of hydrophobic sodium bicarbonate, 2.0 to 3.0 percent of hydroxypropyl methyl cellulose, 1.5 to 2.5 percent of povidone K30, 1.5 to 2.5 percent of polyethylene glycol, 0.5 to 1.0 percent of magnesium stearate and 15 to 25 percent of anhydrous lactose. According to the effervescent tablet, a double-layer microencapsulation isolation technology is adopted, direct contact of acid / alkali / active ingredients is blocked, the available chlorine degradation rate and dust pollution are greatly reduced through room-temperature storage, no organic solvent is left in the preparation process, and the product meets the requirements of green veterinary drugs.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of veterinary drug preparation, and particularly relates to a high-stability sodium dichloroisocyanurate veterinary effervescent tablet and a preparation method thereof. BACKGROUND

[0002] At present, only sodium dichloroisocyanurate powder exists in the domestic field of veterinary disinfection, and the use thereof needs manual weighing, has low dissolution efficiency, and has high dust pollution risk. In view of the disinfection scenes of poultry houses, livestock pens, appliances and breeding eggs, it is urgent to develop convenient and accurate dosage form upgrading products.

[0003] The effervescent tablet dosage form is developed to realize "dissolution by throwing into water", which can not only eliminate weighing errors and dust hazards, but also solve the effective chlorine stability problem through process optimization, and improve the sterilization capacity.

[0004] Based on this, the application is developed. SUMMARY

[0005] The application aims to overcome the defects of the prior art and provide a high-stability sodium dichloroisocyanurate veterinary effervescent tablet. The effervescent tablet adopts double-layer microencapsulation isolation technology to block the direct contact of acid / alkali / active ingredients, greatly reduces the effective chlorine degradation rate and dust pollution in room temperature storage, and has no organic solvent residue in the preparation process, so that the product meets the requirements of green veterinary drugs.

[0006] Another object of the application is to provide a preparation method of the high-stability sodium dichloroisocyanurate veterinary effervescent tablet.

[0007] A third object of the application is to provide experimental data of quality stability of the high-stability sodium dichloroisocyanurate veterinary effervescent tablet and the killing effect on bacteria.

[0008] To achieve the above object, the application adopts the following technical solutions: A high-stability sodium dichloroisocyanurate veterinary effervescent tablet is prepared from the following raw materials in percentage by weight: microencapsulated sodium dichloroisocyanurate 40-50%, hydrophobic sodium bicarbonate 25-30%, hydroxypropyl methylcellulose (preferably HPMCE5) 2.0-3.0%, povidone K30 1.5-2.5%, polyethylene glycol (preferably polyethylene glycol 6000) 1.5-2.5%, magnesium stearate 0.5-1.0%, and anhydrous lactose 15-25%.

[0009] As a preferred embodiment, the high-stability sodium dichloroisocyanurate veterinary effervescent tablet is prepared from the following raw materials in percentage by weight: microencapsulated sodium dichloroisocyanurate 40%, hydrophobic sodium bicarbonate 30%, hydroxypropyl methylcellulose 3.0%, povidone K30 2.2%, polyethylene glycol 6000 1.5%, magnesium stearate 1.0%, and anhydrous lactose 22.3%.

[0010] As a preferred, the high stability sodium dichloroisocyanurate veterinary effervescent tablet is mainly prepared from the following raw materials in percentage by weight: microencapsulated sodium dichloroisocyanurate 45%, hydrophobic sodium bicarbonate 27.5%, hydroxypropyl methylcellulose 2.5%, povidone K30 2.0%, polyethylene glycol 6000 2.0%, magnesium stearate 0.8%, anhydrous lactose 20.2%.

[0011] As a preferred, the high stability sodium dichloroisocyanurate veterinary effervescent tablet is mainly prepared from the following raw materials in percentage by weight: microencapsulated sodium dichloroisocyanurate 45%, hydrophobic sodium bicarbonate 27.5%, hydroxypropyl methylcellulose 2.5%, povidone K30 2.0%, polyethylene glycol 6000 2.0%, magnesium stearate 0.8%, anhydrous lactose 20.2%.

[0012] Specifically, the microencapsulated sodium dichloroisocyanurate is prepared by the following steps: sodium dichloroisocyanurate and citric acid-maltodextrin complex are put into a fluidized bed, the inlet air temperature is 40±2℃, and the atomization pressure is 0.25±0.1 MPa, to form a pH buffer microcapsule, and the microcapsule is obtained. The mass ratio of the sodium dichloroisocyanurate to the citric acid-maltodextrin complex can be 1:0.3-0.4.

[0013] Further, the citric acid-maltodextrin complex is prepared by the following steps: after citric acid is crushed, the citric acid is sprayed into a PVP ethanol solution with a concentration of 4-7% in a three-dimensional mixer running at 30±10 rpm for 10-30 min, and then dried after running at 40±10 rpm for 10-30 min to obtain the citric acid-maltodextrin complex; the mass ratio of the citric acid to the maltodextrin can be 1:2-3; and the amount of the PVP ethanol solution is 2-4% of the sum of the mass of the citric acid and the maltodextrin.

[0014] Specifically, the hydrophobic sodium bicarbonate is prepared by the following steps: sodium bicarbonate is coated in a fluidized bed, and a magnesium stearate ethanol suspension is sprayed to form a coating, the inlet air temperature is 40±1℃, the liquid spraying rate is 7-10 mL / min, and the coating thickness is 30±10 μm; the concentration of the magnesium stearate ethanol suspension is 4-7 w / v %.

[0015] The application provides a preparation method of the high stability sodium dichloroisocyanurate veterinary effervescent tablet. 1) Preparation of the adhesive Alcohol phase solution: povidone K30 is dissolved in anhydrous ethanol (magnetic stirring for 30±10 min at room temperature 25±5℃); Aqueous solution: hydroxypropyl methylcellulose is dissolved in purified water, and then swelled for 8-16 h and homogenized. 2) Mix the microencapsulated sodium dichloroisocyanurate, hydrophobic sodium bicarbonate, anhydrous lactose and part of the alcohol phase solution, shear granulation, add the water phase solution and the rest of the alcohol solution, fluidized bed drying to moisture ≤3%, and then granulate; 3) Transfer the granules after granulation to a three-dimensional motion mixer, mix uniformly after adding polyethylene glycol and magnesium stearate, and then press into tablets.

[0016] Specifically, in step 1), the concentration of povidone K30 is 6-10% w / v, and the concentration of hydroxypropyl methylcellulose is 4-6% w / v; in step 2), the rotation speed during shear granulation is 700-900 rpm, and the time is 1-3 min; during fluidized bed drying, the inlet air temperature is 40-50℃, and the material temperature is ≤35℃; the granulation is performed to pass through a 1.0 mm sieve and the fine powder rate is <5%.

[0017] Specifically, in step 3), the mixing speed is 6-10 rpm (to avoid particle breakage), and the mixing time is 15±1 min; after mixing, the material needs to be completed within 4h (to prevent PEG 6000 from absorbing moisture and reducing lubricity); during the tablet pressing process, the pressure is controlled in stages: pre-pressing 5-8 kN (to eliminate the gap between the materials) and main pressing 20 kN±2 kN (pressure holding time 0.5 s, to avoid friction heating). Low-temperature tabletting process is adopted, a pre-cooling screw feeder is added to the material flow, and a cold air system is added to the tablet press to make the temperature of the tabletting cavity be at -10~0℃, and the punch surface is coated with a titanium nitride heat-conducting coating. The granules after granulation are pressed into tablets to obtain the product of the present application.

[0018] Compared with the prior art, the present application has the following advantages and beneficial effects: 1) The present application adopts double-layer microencapsulation isolation technology to block the direct contact of acid / base / active ingredient, which greatly reduces the effective chlorine degradation rate and dust pollution during room temperature storage; 2) The hydrophobic treated sodium bicarbonate and polyethylene glycol 6000 used in the present application improve the dissolution rate and ensure efficient disinfection; 3) The present application adopts low-temperature gradient tabletting process and HPMC E5 / povidone K30 to enhance the tablet structure, which significantly reduces the disintegration time of the drug under the premise of ensuring the hardness of the tablet; 4) The present application adopts a composite binder system to solve the problem of moisture absorption and softening of traditional effervescent tablets; 5) The process of the present application does not have organic solvent residues, and the product meets the requirements of green veterinary drugs. DETAILED DESCRIPTION

[0019] The technical solutions of the present application are further described in detail in the following embodiments, but the scope of protection of the present application is not limited thereto.

[0020] In the following examples, the raw materials used are all ordinary commercially available products that can be directly purchased or prepared by using conventional techniques in the art.

[0021] Preparation of a high-stability sodium dichloroisocyanurate veterinary effervescent tablet Table 1. Composition of each raw material of the effervescent tablets of Examples 1 to 3 The preparation method of the high-stability sodium dichloroisocyanurate veterinary effervescent tablet described above comprises the following steps: 1) Microencapsulated sodium dichloroisocyanurate: sodium dichloroisocyanurate and citric acid-maltodextrin complex are put into a fluidized bed at a mass ratio of 1:0.3 (inlet air temperature 40±2℃, atomization pressure 0.25MPa) to form a pH buffer microcapsule.

[0022] 2) Hydrophobic sodium bicarbonate: sodium bicarbonate is coated by a fluidized bed, and a magnesium stearate ethanol suspension (concentration 5% w / v) is sprayed to form a coating (inlet air temperature 40±1℃, liquid spraying rate 8mL / min), and the coating thickness is 30±10μm.

[0023] 3) Preparation of the binder Alcohol phase solution: povidone K30 is dissolved in anhydrous ethanol (concentration 8% w / v), and magnetic stirring is performed for 30min (25℃); Aqueous solution: HPMC E5 is dissolved in purified water (concentration 5% w / v), and homogenization is performed after swelling for 12h (using a high-pressure homogenizer for 3 cycles, 5min each time, with 1min cooling interval, same below).

[0024] 4) The microencapsulated sodium dichloroisocyanurate, hydrophobic sodium bicarbonate, anhydrous lactose, and 1 / 3 alcohol phase solution are mixed, high-shear granulation is performed (rotational speed 800rpm, time 2min), the aqueous solution and the remaining 2 / 3 alcohol phase solution are added, fluidized bed drying is performed (inlet air 45℃, material temperature ≤35℃) until the moisture content is ≤3%, and the granulation is performed (through a 1.0mm sieve and fine powder rate <5%).

[0025] 5) The granulated particles are transferred to a three-dimensional motion mixer, polyethylene glycol 6000 and magnesium stearate are added and uniformly mixed, a low-temperature tabletting process is used, a pre-cooling screw feeder is added to the material flow, a cold air system is added to the tablet press to make the tabletting cavity temperature be at -10~0℃, and the punch surface is plated with a titanium nitride heat-conducting coating. The granulated particles obtained by tabletting are the product of the present application.

[0026] Wherein: 1, in step 1), the mass ratio of citric acid to maltodextrin in the citric acid-maltodextrin complex is 1:2, and the preparation method is as follows: after the ultrafine pulverization of citric acid, the citric acid is mixed with maltodextrin in a three-dimensional mixer at 30 rpm for 15 min, 3% of PVP ethanol solution (mass concentration 5%) is sprayed, and then the mixture is run at 40 rpm for 20 min, and then dried to obtain the product.

[0027] 2, in step 5), the mixing parameters are 8 rpm (to avoid particle breakage) and 15±1 min.

[0028] 3, after mixing in step 5), the material needs to be tableted within 4 h (to prevent PEG 6000 from absorbing moisture and reducing lubricity).

[0029] 4, in step 5), the tabletting process adopts a staged pressure control: pre-pressing 5-8 kN (to eliminate the gap between the materials) and main pressing 20 kN±2 kN (pressure holding time 0.5 s, to avoid friction heating).

[0030] Comparative Example 1: without microencapsulation, directly mixing acid and base components The composition and its weight percentage are as follows: sodium dichloroisocyanurate 40%, sodium bicarbonate 30%, HPMC E5 3%, povidone K30 2.2%, polyethylene glycol 6000 1.5%, magnesium stearate 1.0%, anhydrous lactose 22.3%; citric acid and maltodextrin are also included, the mass ratio of citric acid to maltodextrin is 1:2, and the ratio of sodium dichloroisocyanurate to the sum of the mass of citric acid and maltodextrin is 1:0.3.

[0031] Preparation method: 1) Preparation of adhesive Alcohol phase solution: povidone K30 is dissolved in anhydrous ethanol (concentration 8% w / v), and magnetic stirring is performed for 30 min (25°C); Aqueous solution: HPMC E5 is dissolved in purified water (concentration 5% w / v), and homogenized after swelling for 12 h.

[0032] 2) Mix sodium dichloroisocyanurate, sodium bicarbonate, citric acid, maltodextrin, anhydrous lactose, and 1 / 3 of the alcohol phase solution, and granulate under high shear (speed 800 rpm, time 2 min), then add the aqueous solution and the remaining 2 / 3 of the alcohol phase solution, and dry in a fluidized bed (inlet air temperature 45°C, material temperature ≤35°C) to a moisture content of ≤3%, and then perform granulation (pass through a 1.0 mm sieve and the fine powder rate is <5%).

[0033] 3) The whole granules are transferred to a three-dimensional motion mixer, and then polyethylene glycol 6000 and magnesium stearate are uniformly mixed, and then a low-temperature tabletting process is adopted, a pre-cooling screw feeder is additionally arranged in the material flow, a cold air system is additionally arranged in the tabletting machine, the temperature of the tabletting cavity is -10-0 ℃, the punch surface is plated with a titanium nitride heat-conducting coating, and the whole granules are tabletted to obtain the product of the application.

[0034] 1. In step 3), the mixing parameters are a rotation speed of 8 rpm (to avoid particle breakage) and a time of 15±1 min.

[0035] 2. In step 3), the material after mixing needs to be tabletted within 4 h (to prevent PEG 6000 from absorbing moisture and reducing lubricity).

[0036] 3. In step 3), the tabletting process adopts a staged pressure control: pre-pressing 5-8 kN (to eliminate the gap between the materials) and main pressing 20 kN±2 kN (pressure holding time 0.5 s, to avoid friction heating).

[0037] Comparative Example 2: The tabletting temperature is increased to 25 ℃ (without refrigeration) The constituent components and their weight percentage proportions are as follows: sodium dichloroisocyanurate 45%, sodium bicarbonate 27.5%, HPMC E5 52.5%, povidone K30 2.0%, polyethylene glycol 6000 2.0%, magnesium stearate 0.8%, and anhydrous lactose 20.2%.

[0038] Preparation method: 1) Microencapsulated sodium dichloroisocyanurate: sodium dichloroisocyanurate and citric acid-maltodextrin complex are put into a fluidized bed at a mass ratio of 1:0.3 (inlet air temperature 40±2 ℃, atomization pressure 0.25 MPa) to form a pH buffer microcapsule.

[0039] 2) Hydrophobic sodium bicarbonate: sodium bicarbonate is coated by a fluidized bed, and then sprayed with a magnesium stearate ethanol suspension (concentration 5% w / v) to obtain a coating (inlet air temperature 40±1 ℃, spraying rate 8 mL / min), and the coating thickness is 30±10 μm.

[0040] 3) Preparation of adhesive Alcohol phase solution: povidone K30 is dissolved in anhydrous ethanol (concentration 8% w / v), and magnetically stirred for 30 min (25 ℃); Aqueous solution: HPMC E5 is dissolved in purified water (concentration 5% w / v), and then swelled for 12 h and homogenized.

[0041] 4) Mix the microencapsulated sodium dichloroisocyanurate, hydrophobic sodium bicarbonate, anhydrous lactose and 1 / 3 alcohol phase solution, high shear granulation (rotation speed 800 rpm, time 2 min), add water phase solution and the remaining 2 / 3 alcohol phase solution, fluidized bed drying (inlet air temperature 45℃, material temperature ≤ 35℃) to moisture ≤ 3%, and perform granulation (pass through 1.0 mm screen and fine powder rate < 5%).

[0042] 5) Transfer the granulated particles to a three-dimensional motion mixer, add polyethylene glycol 6000 and magnesium stearate and mix uniformly, and tablet the granulated particles (tabletting temperature 25℃) to obtain the product of the present application.

[0043] 1. In step 1), the mass ratio of citric acid to maltodextrin in the citric acid-maltodextrin complex is 1:2, and the preparation method is as follows: after ultrafine pulverization of citric acid, the citric acid is mixed with maltodextrin in a three-dimensional mixer at 30 rpm for 15 min, 5% PVP ethanol solution is sprayed (amount 3%), and after running at 40 rpm for 20 min, drying is performed to obtain the product.

[0044] 2. In step 5), the mixing parameters are rotation speed 8 rpm (to avoid particle breakage) and time 15±1 min. 3. In step 5), the material after mixing needs to be completed within 4 h (to prevent PEG 6000 from absorbing moisture and reducing lubricity).

[0045] 4. In step 5), the tabletting process adopts staged pressure control: pre-pressing 5-8 kN (to eliminate material gaps) and main pressing 20 kN±2 kN (pressure holding time 0.5 s to avoid friction heating).

[0046] Comparative Example 3: HPMC 1.5% + povidone K30 1.0% (lower than the lower limit of the patent) The components and their proportions are as follows: microencapsulated sodium dichloroisocyanurate 50%, hydrophobic sodium bicarbonate 25%, HPMC E5 1.5%, povidone K30 1.0%, polyethylene glycol 6000 2.5%, magnesium stearate 0.5%, and anhydrous lactose 19.5%.

[0047] Preparation method: 1. Microencapsulated sodium dichloroisocyanurate: sodium dichloroisocyanurate and citric acid-maltodextrin complex are put into a fluidized bed at a mass ratio of 1:0.3 (inlet air temperature 40±2℃, atomization pressure 0.25 MPa) to form a pH buffer microcapsule.

[0048] 2. Hydrophobic sodium bicarbonate: sodium bicarbonate is coated in a fluidized bed by spraying with a magnesium stearate ethanol suspension (concentration 5% w / v) (inlet air temperature 40±1℃, spraying rate 8 mL / min) to obtain a coating thickness of 30±10 μm.

[0049] 3. Preparation of the binder Alcohol phase solution: Povidone K30 was dissolved in absolute ethanol (concentration 8% w / v), magnetic stirring for 30 min (25℃); Water phase solution: HPMC E5 was dissolved in purified water (concentration 5% w / v), and homogenized after swelling for 12 h.

[0050] 4. Microencapsulated sodium dichloroisocyanurate, hydrophobic sodium bicarbonate, anhydrous lactose and 1 / 3 alcohol phase solution were mixed, and high-shear granulation was performed (rotational speed 800 rpm, time 2 min). The water phase solution and the remaining 2 / 3 alcohol phase solution were added, and fluidized bed drying (inlet air temperature 45℃, material temperature ≤ 35℃) was performed until the moisture content was ≤ 3%. The granules were sized (passing through a 1.0 mm sieve and the fine powder rate < 5%).

[0051] 5. The sized granules were transferred to a three-dimensional motion mixer, and polyethylene glycol 6000 and magnesium stearate were mixed uniformly. Low-temperature tabletting technology was used, a pre-cooling screw feeder was added to the material flow, a cold air system was added to the tabletting machine to make the tabletting chamber temperature at -10~0℃, and the punch surface was coated with a titanium nitride heat-conducting coating. The sized granules were tabletted to obtain the product of the present application.

[0052] 1. In step 1), the mass ratio of citric acid to maltodextrin in the citric acid-maltodextrin complex was 1:2, and the preparation method was as follows: citric acid was ultra-finely pulverized, and then mixed with maltodextrin in a three-dimensional mixer at a speed of 30 rpm for 15 min. A 5% PVP ethanol solution was sprayed (amount 3%), and then mixed at a speed of 40 rpm for 20 min before drying.

[0053] 2. In step 5), the mixing parameters were a rotational speed of 8 rpm (to avoid particle breakage) and a time of 15±1 min.

[0054] 3. In step 5), the material after mixing needed to be tabletted within 4 h (to prevent PEG 6000 from absorbing moisture and reducing lubricity).

[0055] 4. In step 5), the tabletting process used stage-by-stage pressure control: pre-pressing 5-8 kN (to eliminate gaps between the materials) and main pressing 20 kN±2 kN (pressure holding time 0.5 s to avoid friction heating).

[0056] Comparative Example 4: A commercially available sodium dichloroisocyanurate effervescent tablet (content 40%) Dry direct compression process was used: physical mixing was followed by direct tabletting.

[0057] Test Example 1. Test materials Example 1: Patent process (microencapsulation + low-temperature tabletting), content 40%; Example 2: Patent process (microencapsulation + low-temperature tabletting), content 45%; Example 3 Patent process (microencapsulation + low temperature compression), content 50%; Comparative Example 1 Cancel microencapsulation, directly mixed, content 40%; Comparative Example 2 Normal temperature 25℃ compression, content 45%; Comparative Example 3 HPMC 1.5% + povidone K30 1.0% (lower than the patent lower limit), content 50%; Comparative Example 4 Commercial product (dry straight compression), content 40%.

[0058] 2, Test method, see Table 2 below.

[0059] Table 2 Test method used for testing 3, Test results 3.1 Accelerated stability test (40℃ / 75% RH, 3 months) Table 3 Accelerated stability test results From the above table, the process of the application adopts microencapsulation + low temperature compression + reasonable auxiliary material ratio, which can significantly improve the retention rate of effective chlorine, and the effective chlorine retention rate is as high as 94.8%, which is better than 78.3%-86.2% of the comparative examples, and improves the quality stability of the product. At the same time, the appearance of the tablet product does not change, and there is no yellow spot, crack or deliquescence, which is much better than the products of comparative examples 1 to 4.

[0060] 3.2 Disintegration and dissolution performance Table 4 Disintegration and dissolution performance From the above table, the disintegration time of the product of Example 2 in still water is 38s, which is reduced by 63.8%, 28.3% and 67.8% respectively compared with Comparative Examples 1, 2 and 4; the disintegration time of Example 2 in flowing water is 22s, which is reduced by 67.6%, 37.1% and 75.3% respectively compared with Comparative Examples 1, 2 and 4, and there is no residual particle in water for Example 2.

[0061] Therefore, the product of the application can significantly reduce the disintegration time of the drug and improve the dissolution performance.

[0062] 3.3 Bactericidal efficacy (5% solution, 5min) Table 5 Bactericidal efficacy results From the above table, it can be seen that the killing effect of Example 2 on E. coli, S. aureus, C. albicans and B. subtilis can meet the requirements of the national standard, while the killing effect of Comparative Example 1 on C. albicans and B. subtilis does not meet the requirements of the national standard, and the killing effect of Comparative Example 4 on S. aureus, C. albicans and B. subtilis does not meet the requirements of the national standard.

[0063] It can be seen that the product of the present application can effectively improve the bactericidal effect on bacteria by using the microencapsulation process, and the bactericidal effect is significantly higher than that of the commercially available wet granulation product.

[0064] 4. Production feasibility (10 million tablets of continuous tabletting) Table 6. Production feasibility results From the above table, it can be seen that the qualified rate of the tablet product of Example 2 is increased by 7.1% and 5.6% respectively compared with Comparative Examples 2 and 3. It is shown that the process adopted by the present application can improve the qualified rate of industrial production, and there is no sticking and collision phenomenon, and no damage to the mold.

[0065] From the comparative test, it can be seen that the key processes such as microencapsulation isolation, low-temperature tabletting and composite adhesion of the process of the present application have significant advantages in product stability, disintegration rate and safety.

Claims

1. A highly stable sodium dichloroisocyanurate effervescent tablet for veterinary use, characterized in that, It is mainly made of the following raw materials in weight percentage: 40-50% microencapsulated sodium dichloroisocyanurate, 25-30% hydrophobic sodium bicarbonate, 2.0-3.0% hydroxypropyl methylcellulose, 1.5-2.5% povidone K30, 1.5-2.5% polyethylene glycol, 0.5-1.0% magnesium stearate, and 15-25% anhydrous lactose.

2. The highly stable sodium dichloroisocyanurate effervescent tablets for veterinary use as described in claim 1, characterized in that, It is mainly made of the following raw materials in weight percentage: 40% microencapsulated sodium dichloroisocyanurate, 30% hydrophobic sodium bicarbonate, 3.0% hydroxypropyl methylcellulose, 2.2% povidone K30, 1.5% polyethylene glycol, 1.0% magnesium stearate, and 22.3% anhydrous lactose.

3. The highly stable sodium dichloroisocyanurate effervescent tablets for veterinary use as described in claim 1, characterized in that, It is mainly made of the following raw materials in weight percentage: 45% microencapsulated sodium dichloroisocyanurate, 27.5% hydrophobic sodium bicarbonate, 2.5% hydroxypropyl methylcellulose, 2.0% povidone K30, 2.0% polyethylene glycol, 0.8% magnesium stearate, and 20.2% anhydrous lactose.

4. The highly stable sodium dichloroisocyanurate effervescent tablets for veterinary use as described in claim 1, characterized in that, It is mainly made of the following raw materials in weight percentage: 50% microencapsulated sodium dichloroisocyanurate, 25% hydrophobic sodium bicarbonate, 2.0% hydroxypropyl methylcellulose, 1.8% povidone K30, 2.5% polyethylene glycol, 0.5% magnesium stearate, and 18.2% anhydrous lactose.

5. The highly stable sodium dichloroisocyanurate effervescent tablets for veterinary use as described in claim 1, characterized in that, The microencapsulated sodium dichloroisocyanurate was prepared by the following steps: sodium dichloroisocyanurate and citric acid-maltodextrin complex were fed into a fluidized bed, with an inlet air temperature of 40±2℃ and an atomization pressure of 0.25±0.1MPa, to form pH buffer microcapsules. The mass ratio of sodium dichloroisocyanurate to the citric acid-maltodextrin complex is 1:0.3-0.

4.

6. The highly stable sodium dichloroisocyanurate effervescent tablets for veterinary use as described in claim 5, characterized in that, The citric acid-maltodextrin complex was prepared by the following steps: citric acid was pulverized and mixed with maltodextrin in a three-dimensional mixer for 10-30 minutes, then a 4-7% PVP ethanol solution was sprayed in, and the mixture was dried after running for 10-30 minutes. The mass ratio of citric acid to maltodextrin was 1:2-3. The amount of PVP ethanol solution used was 2-4% of the sum of the masses of citric acid and maltodextrin.

7. The highly stable sodium dichloroisocyanurate effervescent tablets for veterinary use as described in claim 1, characterized in that, The hydrophobic sodium bicarbonate was prepared by the following steps: sodium bicarbonate was coated by fluidized bed coating and sprayed with magnesium stearate ethanol suspension (inlet air temperature 40±1℃, spraying rate 7-10 mL / min), coating thickness 30±10μm; the concentration of magnesium stearate ethanol suspension was 4-7 w / v.

8. The method for preparing highly stable sodium dichloroisocyanurate effervescent tablets for veterinary use according to any one of claims 1 to 7, characterized in that, Includes the following steps: 1) Adhesive preparation Alcoholic phase solution: Povidone K30 dissolved in anhydrous ethanol; Aqueous solution: Hydroxypropyl methylcellulose was dissolved in purified water and homogenized after swelling for 8-16 hours; 2) Mix microencapsulated sodium dichloroisocyanurate, hydrophobic sodium bicarbonate, anhydrous lactose and a portion of the alcohol phase solution, shear and granulate, add aqueous phase solution and the remaining alcohol phase solution, fluidize and dry to moisture ≤3%, and then granulate. 3) Transfer the granulated particles to a three-dimensional motion mixer, add polyethylene glycol and magnesium stearate, mix evenly, and then compress into tablets.

9. The method for preparing highly stable sodium dichloroisocyanurate effervescent tablets for veterinary use as described in claim 8, characterized in that, In step 1), the concentration of povidone K30 is 6-10% w / v, and the concentration of hydroxypropyl methylcellulose is 4-6% w / v; in step 2), the rotation speed is 700-900 rpm and the time is 1-3 min during shear granulation; during fluidized bed drying, the inlet air temperature is 40-50℃ and the material temperature is ≤35℃; granulation is performed until the particles pass through a 1.0 mm sieve and the fine powder rate is <5%.

10. The method for preparing highly stable sodium dichloroisocyanurate effervescent tablets for veterinary use as described in claim 8, characterized in that, In step 3), the mixing speed is 6-10 rpm and the mixing time is 15±1 min; the mixed material needs to be tableted within 4 hours; the tableting process adopts staged pressure control: pre-compression 5-8kN and main pressure 20kN±2kN, holding time 0.5s; the temperature of the tableting chamber is -10~0℃.

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