A sustained-release lansoprazole tablet and a method for preparing the same

Abstract

This invention provides a lansoprazole sustained-release tablet, comprising a tablet core and a coating layer. The tablet core includes sustained-release granules, immediate-release granules, and other pharmaceutically acceptable excipients. The coating layer is made of enteric-coated film-coating powder. The lansoprazole sustained-release tablet provided by this invention provides rapid onset of action and maintenance of blood drug concentration upon oral administration, high bioavailability, and few side effects. It improves the solubility of lansoprazole, eliminating the need for surfactant solubilization. It also exhibits high acid stability, eliminating the need for an isolation coating. The lansoprazole sustained-release tablet of this invention employs a two-stage granulation method, both of which are dry granulation, separately preparing sustained-release and immediate-release granules. This avoids the high-temperature drying process following traditional wet granulation, thus improving the stability of lansoprazole.

Description

Technical Field

[0001] This invention belongs to the field of pharmaceutical formulation technology, specifically relating to a lansoprazole sustained-release tablet and its preparation method. Background Technology

[0002] Lansoprazole is a new generation of proton pump inhibitor anti-ulcer drugs following omeprazole. Structurally similar to omeprazole, it exhibits superior chemical stability and therapeutic efficacy due to the introduction of a fluorine atom. Lansoprazole was developed by Takeda Pharmaceutical Company of Japan in 1994 and first marketed in France. It began clinical application in my country in 1998.

[0003] Lansoprazole is a white to brownish-white odorless crystalline powder with very low solubility in water. It is unstable under acidic conditions and is easily destroyed in gastric acid. When formulated into tablets or capsules, it is slowly absorbed orally, has low bioavailability, and poor stability, seriously affecting the drug's clinical efficacy. Studies have also found that lansoprazole is unstable to moisture, heat, and light, and is highly susceptible to degradation and oxidation reactions, producing inactive impurities, leading to a decrease in the content of the active ingredient. Furthermore, degradation products can cause allergic reactions in users. To address the instability of lansoprazole in gastric acid, current technologies typically prepare it as enteric-coated tablets or enteric-coated granules and then encapsulate it. Since the coating solution is acidic, it affects the stability of lansoprazole. Enteric-coated tablets or capsules usually have an isolation layer between the tablet core / granule core and the enteric coating to improve the stability of the formulation. However, the preparation process for this isolation layer is complex and costly. Simultaneously, current technologies often add solubilizers such as sodium dodecyl sulfate to address dissolution issues. However, solubilizers have limited effect on improving the dissolution rate of tablets, and sodium dodecyl sulfate has poor compatibility with lansoprazole, which can affect the stability of the lansoprazole drug.

[0004] In addition, patent CN109692161A discloses a lansoprazole sustained-release formulation, which consists of a tablet core formulation and a coating layer formulation. The tablet core is composed of lansoprazole, lactose, hydroxypropyl methylcellulose, cross-linked povidone, talc, and magnesium stearate. The coating layer formulation is composed of two or more of ethyl cellulose, hydroxypropyl methylcellulose, polyacrylic acid resin, microcrystalline cellulose, and magnesium stearate. However, this sustained-release formulation hardly dissolves within 2 hours, has a slow onset of action, low bioavailability, and poor stability. Patent CN104013580B discloses a lansoprazole sustained-release microsphere, which maintains the stability of lansoprazole by adding antioxidants. It avoids the damage of lansoprazole by high temperature through spray drying granulation and spray coating, and requires strict control of the preparation process.

[0005] Although existing technologies have disclosed various enteric-coated tablets or capsules for lansoprazole, obtaining lansoprazole tablets with high stability, simple preparation process, rapid onset of action, and high bioavailability remains an important research topic for researchers. Summary of the Invention

[0006] In view of this, the purpose of this invention is to provide a lansoprazole enteric sustained-release tablet with high stability, simple preparation process, rapid onset of action, and high bioavailability, as well as a method for preparing the same.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A lansoprazole sustained-release tablet includes a tablet core and a coating layer. The tablet core includes sustained-release granules, immediate-release granules, and other pharmaceutically acceptable excipients. The coating layer is made of enteric-coated film-coating powder.

[0009] Preferably, the sustained-release particles in the tablet core contain lansoprazole, sucrose powder, magnesium hydroxide, and hydroxypropyl methylcellulose.

[0010] Preferably, the immediate-release particles in the tablet core contain lansoprazole, sucrose powder, magnesium hydroxide, and croscarmellose sodium.

[0011] Preferably, the sustained-release particles in the tablet core contain 15-20 parts of lansoprazole, 10-30 parts of sucrose powder, 30-45 parts of magnesium hydroxide, and 180-220 parts of hydroxypropyl methylcellulose.

[0012] More preferably, the sustained-release particles in the tablet core contain 15-20 parts of lansoprazole, 15-25 parts of sucrose powder, 35-40 parts of magnesium hydroxide, and 200-220 parts of hydroxypropyl methylcellulose.

[0013] Preferably, the immediate-release granules in the tablet core contain 10-15 parts of lansoprazole, 15-30 parts of sucrose powder, 20-30 parts of magnesium hydroxide, and 2-5 parts of croscarmellose sodium.

[0014] More preferably, the fast-release granules in the tablet core contain 10-15 parts of lansoprazole, 20-25 parts of sucrose powder, 25 parts of magnesium hydroxide, and 3 parts of croscarmellose sodium.

[0015] In some embodiments, the sustained-release granules contain 15 parts of lansoprazole, and the immediate-release granules contain 15 parts of lansoprazole.

[0016] In some embodiments, the sustained-release granules contain 20 parts of lansoprazole, and the immediate-release granules contain 10 parts of lansoprazole.

[0017] Preferably, the other pharmaceutically acceptable excipients include disintegrants, lubricants, and flow aids; the disintegrant is selected from one of croscarmellose sodium, carboxymethyl starch sodium, croscarmellose, low-substituted hydroxypropyl cellulose, and calcium carboxymethyl cellulose, more preferably croscarmellose sodium; the lubricant is selected from one of stearic acid, magnesium stearate, sodium stearyl fumarate, polyethylene glycol 4000, and polyethylene glycol 6000, more preferably magnesium stearate; the flow aid is selected from one of colloidal silica and talc, more preferably colloidal silica.

[0018] Preferably, the amount of the disintegrant is 5-10 parts by weight.

[0019] Preferably, the amount of the lubricant is 3-5 parts by weight.

[0020] Preferably, the amount of the gliding agent is 1-2 parts by weight.

[0021] Preferably, the lansoprazole tablets provided by the present invention dissolve 25-40% in 0.5h, 45-60% in 1h, 60-75% in 1.5h, 90-97% in 4h, and ≥95% in 5h in a phosphate buffer at pH 6.8.

[0022] A method for preparing lansoprazole sustained-release tablets involves a two-stage granulation process, both of which are dry granulation. Sustained-release granules and immediate-release granules are prepared separately. After granulation, the sustained-release granules, immediate-release granules, and other pharmaceutically acceptable excipients are taken, mixed evenly, and then compressed into tablets to obtain tablet cores. The tablet cores are then coated with enteric coating to obtain lansoprazole sustained-release tablets.

[0023] Preferably, the preparation method of the sustained-release granules is as follows: weigh the prescribed amount of lansoprazole, sucrose powder and magnesium hydroxide, crush and sieve them, mix them and perform the first dry granulation; crush and sieve the prepared granules again, mix them evenly with hydroxypropyl methylcellulose, and perform the second dry granulation to obtain the sustained-release granules.

[0024] Preferably, the preparation method of the immediate-release granules is as follows: weigh the prescribed amount of lansoprazole, sucrose powder, and magnesium hydroxide, pulverize and sieve them, mix them, and perform the first dry granulation; after pulverizing and sieving the prepared granules again, mix them evenly with cross-linked carboxymethyl cellulose sodium, and perform the second dry granulation to obtain the immediate-release granules.

[0025] Preferably, the method for preparing the lansoprazole sustained-release tablets includes the following steps:

[0026] 1) Preparation of sustained-release granules: Weigh lansoprazole, sucrose powder, and magnesium hydroxide powder, sieve, mix evenly, and then perform the first dry granulation using a dry granulator. After the prepared granules are pulverized and sieved again, they are mixed evenly with hydroxypropyl methylcellulose and then performed the second dry granulation using a dry granulator. After granulation, the granules are sieved for later use.

[0027] 2) Preparation of immediate-release granules: Weigh lansoprazole, sucrose powder, and magnesium hydroxide, crush and sieve them, mix them evenly, and perform the first granulation using a dry granulator. After crushing and sieving the prepared granules again, add sodium carboxymethyl cellulose and mix evenly. Perform the second dry granulation using a dry granulator. After granulation, sieve them for later use.

[0028] 3) Preparation of tablet core: After uniformly mixing the sustained-release granules, immediate-release granules and other pharmaceutically acceptable excipients prepared in steps 1) and 2), the mixture is compressed into tablets to obtain the tablet core.

[0029] 4) Preparation of enteric coating: Add enteric film coating powder to a solvent to coat the tablet core, thus obtaining lansoprazole sustained-release tablets.

[0030] Preferably, the enteric film coating material in step 4) is selected from... L100 L100-55 One of the L30D-55s.

[0031] Preferably, the solvent for dissolving the enteric film coating material in step 4) is 70% ethanol.

[0032] Preferably, the weight gain percentage of the enteric coating in step 4) is 3-4%.

[0033] Overall, the lansoprazole sustained-release tablets prepared by this invention have the following advantages over the prior art:

[0034] (1) It has high acid stability, does not require isolation clothing, and has a simple process.

[0035] (2) By using a combination of sustained-release granules and immediate-release granules, oral administration can quickly take effect and maintain blood drug concentration, with high bioavailability and few side effects.

[0036] (3) Improved the solubility of lansoprazole, eliminating the need for surfactants to solubilize it.

[0037] (4) The two-stage granulation method is adopted, and both are dry granulation, which avoids the high-temperature drying process after traditional wet granulation and improves the stability of lansoprazole. Detailed Implementation

[0038] The present invention will be further illustrated by the following embodiments. It should be understood that the embodiments of the present invention are merely for illustrating the present invention and are not intended to limit the present invention. Therefore, any simple improvements to the present invention under the premise of the method of the present invention are within the scope of protection of the present invention.

[0039] All raw materials used in this invention can be purchased commercially. The sucrose powder used in this invention is sucrose (C 12 H 22 O 11 A mixture of sucrose and corn starch, ground into a fine powder, containing not less than 95.0% sucrose.

[0040] Example 1

[0041] Prescription: See Table 1 below.

[0042] Table 1:

[0043]

[0044] Preparation method:

[0045] 1) Take 20g of lansoprazole, 25g of sucrose powder and 40g of magnesium hydroxide, crush and sieve them, mix them and perform the first dry granulation; crush the prepared granules again and sieve them, add them together with 200g of HPMC into the mixer and mix them thoroughly, perform the second dry granulation after mixing and sieve them to obtain lansoprazole sustained-release granules.

[0046] 2) Take 10g of lansoprazole, 25g of sucrose powder and 25g of magnesium hydroxide, crush and sieve them, mix them and perform the first dry granulation; crush the prepared granules again and sieve them, add them together with 3g of cross-linked carboxymethyl cellulose sodium into a mixer and mix them thoroughly, perform the second dry granulation after mixing and sieve them to obtain lansoprazole immediate release granules.

[0047] 3) Take 7g of cross-linked sodium carboxymethyl cellulose, 1.8g of colloidal silica, and the lansoprazole sustained-release granules and immediate-release granules prepared in steps 1) and 2) and add them to a mixer. After mixing thoroughly, add 3.2g of magnesium stearate and mix. Compress into 1000 tablets.

[0048] 4) Take 15g of Eucerin enteric coating powder, add it to 187.5g of 70% ethanol and stir for 45min. Coat the prepared tablet core with a coating machine, with a coating weight gain of 3%. After drying, lansoprazole enteric coated tablets are obtained.

[0049] Example 2

[0050] Prescription: See Table 2 below.

[0051] Table 2:

[0052]

[0053] Preparation method: Same as in Example 1.

[0054] Example 3

[0055] Prescription: See Table 3 below.

[0056] Table 3:

[0057]

[0058]

[0059] Preparation method: Same as in Example 1.

[0060] Example 4

[0061] Prescription: See Table 4 below.

[0062] Table 4:

[0063]

[0064] Preparation method: Same as in Example 1.

[0065] Example 5

[0066] Prescription: See Table 5 below.

[0067] Table 5:

[0068]

[0069]

[0070] Preparation method: Same as in Example 1.

[0071] Example 6

[0072] Prescription: See Table 6 below.

[0073] Table 6:

[0074]

[0075] Preparation method: Same as in Example 1.

[0076] Example 7

[0077] Prescription: See Table 7 below.

[0078] Table 7:

[0079]

[0080]

[0081] Preparation method: Same as in Example 1.

[0082] Example 8

[0083] Prescription: See Table 8 below.

[0084] Table 8:

[0085]

[0086] Preparation method: Same as in Example 1.

[0087] Example 9

[0088] Prescription: See Table 9 below.

[0089] Table 9:

[0090]

[0091]

[0092] Preparation method: Same as in Example 1.

[0093] Example 10

[0094] Prescription: Same as in Example 1.

[0095] Preparation method:

[0096] 1) Weigh out the prescribed amounts of lansoprazole, sucrose powder, magnesium hydroxide, and hydroxypropyl methylcellulose and add them to a mixer to mix thoroughly. Granulate the mixture using a dry granulator and sieve it to obtain lansoprazole sustained-release granules.

[0097] 2) Weigh out the prescribed amounts of lansoprazole, sucrose powder, magnesium hydroxide, and croscarmellose sodium and add them to a mixer to mix thoroughly. Granulate the mixture using a dry granulator and sieve it to obtain lansoprazole immediate-release granules.

[0098] 3) Weigh out the prescribed amount of cross-linked sodium carboxymethyl cellulose, colloidal silica, and the lansoprazole sustained-release granules and immediate-release granules prepared in steps 1) and (2), add them to a mixer, mix thoroughly, add magnesium stearate, mix, and compress into tablets;

[0099] 4) Take 15g of Eucerin enteric coating powder, add it to 187.5g of 70% ethanol and stir for 45min. Coat the prepared tablet core with a coating machine, with a coating weight gain of 3%. After drying, lansoprazole enteric coated tablets are obtained.

[0100] Comparative Example 1

[0101] Prescription: See Table 10 below.

[0102] Table 10:

[0103]

[0104]

[0105] Preparation method: Same as in Example 1.

[0106] Comparative Example 2

[0107] Prescription: See Table 11 below.

[0108] Table 11:

[0109]

[0110] Preparation method: Same as in Example 1.

[0111] Comparative Example 3

[0112] Prescription: See Table 12 below.

[0113] Table 12:

[0114]

[0115]

[0116] Preparation method:

[0117] 1) Take the prescribed amount of lansoprazole, sucrose powder, and magnesium hydroxide, grind and sieve them, mix them and perform the first dry granulation; grind and sieve the prepared granules again, add them together with 200g HPMC into the mixer and mix thoroughly, then perform the second dry granulation and sieve.

[0118] 2) Take the prescribed amount of cross-linked sodium carboxymethyl cellulose, colloidal silica and the granules prepared in step 1) and add them to a mixer. After mixing thoroughly, add magnesium stearate and mix. Compress into 1000 tablets.

[0119] 3) Take 15g of Eucerin enteric coating powder, add it to 187.5g of 70% ethanol and stir for 45min. Coat the prepared tablet core with a coating machine, with a coating weight gain of 3%. After drying, lansoprazole enteric coated tablets are obtained.

[0120] Comparative Example 4

[0121] Prescription: See Table 13 below.

[0122] Table 13:

[0123]

[0124] Preparation method:

[0125] 1. Preparation of tablet core: Weigh an appropriate amount of lansoprazole powder, add the excipients in the table above, pass through a 20-mesh sieve to make wet granules, dry at 50℃, pass the dry granules through a 15-mesh sieve to granulate, add 1% magnesium stearate and mix evenly, and compress to obtain tablet core.

[0126] 2. Preparation of coating layer: After mixing all the auxiliary materials of the coating layer, wet granules are made by passing through a 20-mesh sieve, dried at 50℃, and the dry granules are sized by passing through a 20-mesh sieve. Then, 1% magnesium stearate is added and mixed well to make the coating material.

[0127] 3. Coating and Compression: Weigh the prescribed amount of coating material and divide it into two portions in a 1:1 ratio. Fill one portion of the coating material into the die, place the tablet core in the center of the upper surface of the coating material, then fill the remaining portion of the coating material into the die, and compress again to obtain the desired sustained-release tablets. Each tablet contains 20 mg of lansoprazole.

[0128] Comparative Example 5

[0129] Prescription: See Table 14 below.

[0130] Table 14:

[0131]

[0132] Preparation method:

[0133] 1) Preparation of sustained-release granules: Lansoprazole is mixed with hydroxypropyl methylcellulose and xanthan gum and stirred to form a uniform mixture. The mixture is then extruded into flakes or blocks. The flakes or blocks are then pulverized so that they can all pass through the No. 2 sieve of the Chinese Pharmacopoeia. Microcrystalline cellulose and magnesium stearate are added to the sieved granules and stirred evenly to form a sustained-release layer mixture.

[0134] 2) Preparation of immediate-release granules: Lansoprazole is added to crospovidone and microcrystalline cellulose and stirred to form a uniform mixture. The mixture is then extruded into flakes or blocks. The flakes or blocks are then pulverized so that they can all pass through the No. 2 sieve of the Chinese Pharmacopoeia. Magnesium stearate is added to the sieved granules and stirred evenly to form an immediate-release layer mixture.

[0135] 3) Compress the immediate-release layer mixture and the sustained-release layer mixture into bilayer tablets using a bilayer tableting machine;

[0136] 4) Coat the prepared medicine using a coating machine, with a coating weight gain of 3%.

[0137] Verification Implementation Examples

[0138] 1. Stability test

[0139] Lansoprazole sustained-release formulations prepared in Examples 1-10 and Comparative Examples 1-5, as well as commercially available lansoprazole enteric-coated capsules, were packaged in resealable bags. Experimental conditions were: temperature 40℃±2℃, humidity 75%±5%. Samples were taken at 0, 3, and 6 months. The enteric coating was removed, and the color of the tablet core or microcapsules was observed. The content and related parameters were determined, and the results are shown in Table 15 below.

[0140] Table 15: Results of Accelerated Stability Test

[0141]

[0142]

[0143] As can be seen from the above results, the lansoprazole enteric sustained-release formulation prepared by the present invention exhibits excellent stability within 6 months under accelerated experimental conditions, with no change in appearance, content, or related substances.

[0144] 2. Dissolution test in pH 6.8 phosphate buffer solution

[0145] Lansoprazole preparations prepared in Examples 1-10 and Comparative Examples 1-5 were used as the test group. Dissolution and release were determined according to the method (Chinese Pharmacopoeia, Part IV, General Chapter 0931, Method 1, Method 2). 1000 ml of hydrochloric acid solution was used as the dissolution medium, and the rotation speed was 100 rpm. After 120 minutes, the basket was immediately raised above the liquid surface, the hydrochloric acid solution was discarded, and 1000 ml of preheated (pH 6.8) phosphate buffer solution at 37°C was immediately added. The rotation speed remained unchanged, and the procedure was continued. After 30, 60, 90, 120, 150, 180, 240, and 300 minutes, the dissolution rate was determined. Filter the solution, accurately measure 5 ml of the filtrate, accurately add 1 ml of 0.15 mol / L sodium hydroxide solution, and shake well to prepare the test solution. Separately, accurately weigh approximately 15 mg of lansoprazole reference standard (China Food and Drug Inspection Institute, batch number 100709-200902, purity 99.8%), place it in a 100 ml volumetric flask, dissolve and dilute to the mark with methanol, and shake well. Accurately measure 5 ml of this solution and place it in a 25 ml volumetric flask, dilute to the mark with phosphate buffer solution, and shake well. Accurately measure 5 ml of this solution and add 1 ml of 0.15 mol / L sodium hydroxide solution, and shake well to prepare the reference solution. Discard both the test solution and the reference solution, and determine the dissolution rate of the formulation at 30, 60, 90, 120, 150, 180, 240, and 300 minutes according to the method under the Assay section. The dissolution rate results are shown in Table 16 below.

[0146] Table 16 Dissolution of lansoprazole sustained-release formulation at different time points in pH 6.8 phosphate buffer.

[0147] Test sample 30min 60min 90min 120min 150min 180min 240min 300min Example 1 30.4 55.6 63.5 71.0 79.2 88.5 94.3 99.8 Example 2 38.2 58.6 68.0 76.8 83.1 87.6 96.8 99.0 Example 3 25.6 46.8 57.9 68.8 78.6 89.7 95.4 100.1 Example 4 39.5 59.7 67.5 74.3 82.6 85.4 94.9 99.2 Example 5 31.5 53.6 65.7 73.2 80.5 87.6 93.4 98.8 Example 6 38.9 61.6 73.6 81.7 87.9 93.2 96.7 99.9 Example 7 18.7 36.8 42.5 55.5 70.0 78.3 86.9 93.6 Example 8 34.5 64.0 79.6 88.1 92.8 98.0 98.9 97.6 Example 9 17.8 30.7 40.2 53.9 64.8 73.5 81.1 89.0 Example 10 23.4 36.7 47.5 63.8 72.6 80.0 88.2 93.5 Comparative Example 1 25.1 39.0 48.7 56.6 64.8 73.9 85.4 89.3 Comparative Example 2 22.9 37.9 46.1 53.9 63.0 71.2 83.5 86.8 Comparative Example 3 17.9 23.5 29.8 37.6 52.9 68.1 72.8 76.7 Comparative Example 4 0 2.8 4.7 7.6 65.9 98.7 98.6 —— Comparative Example 5 8.9 18.0 21.5 30.8 43.2 57.5 62.6 65.4

[0148] 3. Bioavailability Experiment

[0149] Lansoprazole formulations prepared in Examples 1-10 and Comparative Examples 1-5 were used as test samples. Ordinary Beagle dogs were used as experimental animals in a crossover design. The reference formulation was commercially available lansoprazole enteric-coated capsules. (30mg / tablet). When administering the medication, open the dog's mouth and insert one tablet of the self-made formulation / reference formulation into the dog's throat, followed by 10mL of purified water. Timing begins after the dog swallows. Collect approximately 0.2mL of blood samples before administration and at 0.25, 0.5, 1, 1.5, 2, 3, 4, 6, 8, 24, 48, and 72 hours after administration. Place the samples in heparinized centrifuge tubes, centrifuge at 4000g for 10 minutes, and collect the supernatant. Freeze at -80℃ for later use. The time error for blood collection points within 1 hour is ±2min; for blood collection points from 1 hour to 24 hours, the time error is ±10min; and for blood collection points 24 hours and above, the time error is ±1 hour. Keep the blood on ice from collection to centrifugation. The developed UPLC-MS / MS method was used to determine the lansoprazole content in canine plasma. The pharmacokinetic parameters of lansoprazole in plasma after oral administration to dogs were calculated using DAS2.1.1 pharmacokinetic data processing software. If the blood collection time does not match the expected time, the pharmacokinetic parameters are calculated based on the actual blood collection time, and the results are shown in Table 17.

[0150] Table 17 Relative bioavailability of lansoprazole extended-release formulations

[0151] Group Cmax(μg / ml) Relative bioavailability (%) Example 1 0.688±0.254 167.1±18.6 Example 2 0.735±0.236 159.5±17.3 Example 3 0.697±0.259 147.4±18.5 Example 4 0.437±0.266 138.6±19.2 Example 5 0.303±0.198 152.9±12.3 Example 6 0.721±0.202 118.6±14.5 Example 7 0.367±0.231 104.4±14.3 Example 8 0.876±0.128 114.9±14.3 Example 9 0.384±0.187 103.8±11.3 Example 10 0.358±0.245 112.5±15.6 Comparative Example 1 0.547±0.226 81.5±12.3 Comparative Example 2 0.479±0.141 76.9±16.8 Comparative Example 3 0.237±0.135 85.6±15.4 Comparative Example 4 0.334±0.251 67.4±14.9 Comparative Example 5 0.279±143 60.0±15.8

Claims

1. A sustained release tablet of lansoprazole, characterized in that, The tablet comprises a core and a coating layer. The core includes sustained-release granules, immediate-release granules, and other pharmaceutically acceptable excipients. The coating layer is made of enteric-coated film-coating powder. The sustained-release granules in the core contain 15-20 parts of lansoprazole, 10-30 parts of sucrose powder, 30-45 parts of magnesium hydroxide, and 180-220 parts of hydroxypropyl methylcellulose. The immediate-release granules in the core contain 10-15 parts of lansoprazole, 15-30 parts of sucrose powder, 20-30 parts of magnesium hydroxide, and 2-5 parts of croscarmellose sodium.

2. The sustained-release tablet as described in claim 1, characterized in that, Other pharmaceutically acceptable excipients include disintegrants, lubricants, and glidants.

3. The sustained-release tablet as described in claim 2, characterized in that, The amount of the disintegrant is 5-10 parts by weight, the amount of the lubricant is 3-5 parts, and the amount of the gliding agent is 1-2 parts.

4. A method for preparing lansoprazole sustained-release tablets according to any one of claims 1-3, characterized in that, A two-stage granulation method, both dry granulation, was used to prepare sustained-release granules and immediate-release granules respectively. After granulation, the sustained-release granules, immediate-release granules, and other pharmaceutically acceptable excipients were taken, mixed evenly, and then compressed into tablets to obtain tablet cores. The tablet cores were then coated with enteric coating to obtain lansoprazole sustained-release tablets.

5. The method for preparing sustained-release tablets as described in claim 4, characterized in that, The preparation method of the sustained-release granules is as follows: weigh lansoprazole, sucrose powder and magnesium hydroxide, crush and sieve them, mix them and perform the first dry granulation; crush and sieve the prepared granules again, mix them evenly with hydroxypropyl methylcellulose, and perform the second dry granulation to obtain sustained-release granules.

6. The method for preparing sustained-release tablets as described in claim 4, characterized in that, The preparation method of the immediate-release granules is as follows: weigh the prescribed amount of lansoprazole, sucrose powder, and magnesium hydroxide, pulverize and sieve them, mix them, and perform the first dry granulation; after pulverizing and sieving the prepared granules again, mix them evenly with cross-linked carboxymethyl cellulose sodium, and perform the second dry granulation to obtain the immediate-release granules.

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