A kind of acetaminophen tablet and preparation method thereof

Abstract

The invention discloses a paracetamol tablet and a preparation method thereof, and belongs to the technical field of pharmaceutical preparation preparation. By weight, the paracetamol tablet includes 86.88 parts of paracetamol, 4.52 parts of adhesive, 2.90 parts of disintegrant, 5.21 parts of filler and 0.49 parts of lubricant. The present invention reduces the types and amounts of auxiliary materials by improving the formula of paracetamol tablets and combining a special preparation process, and the main drug accounts for a high proportion. At the same time, the preparation process is simple, the production cost is low, and the production is safe. It does not require boiling water or organic solvent slurrying, and the degree of mechanization is high. It is suitable for industrial production, solves the problem of poor compressibility of paracetamol tablets, and the prepared paracetamol tablets are small in weight, which can minimize the management and inspection costs of auxiliary materials, improve the compliance of patients with medication, and the product quality is stable, the dissolution is complete, the quality is consistent with the original preparation, and it does not contain surfactants, which meets the BE exemption requirements of the consistency evaluation of generic drugs of the State Food and Drug Administration.

Description

Technical Field

[0001] The invention relates to the technical field of pharmaceutical preparation preparation, in particular to an acetaminophen tablet and a preparation method thereof. Background Art

[0002] Paracetamol, chemically named 4'-hydroxyacetanilide and with molecular formula C8H9NO2, is an antipyretic and analgesic drug that selectively inhibits the synthesis of prostaglandins in the hypothalamic temperature regulation center by inhibiting cyclooxygenase, leading to peripheral vasodilation and sweating, thus achieving an antipyretic effect.

[0003] In 1878, Harmon Northrop Morse first synthesized acetaminophen at Johns Hopkins University. Acetaminophen is available for sale both at home and abroad, and has been available for sale as an over-the-counter drug in China for many years. Acetaminophen has the characteristics of rapid and complete oral absorption, low toxicity and side effects, and safe use. It is the most widely used and largest-volume over-the-counter antipyretic and analgesic drug in the world. Acetaminophen crystals are brittle and crushable materials with typical molar compression characteristics. They are long needle-shaped crystals with great brittleness, weak plastic deformation ability, and poor compressibility. Tableting is prone to problems such as "splitting" or "falling off the cover", which affects the quality of the product. In addition, because the specifications of acetaminophen tablets (0.5g) are large, if too many excipients are used, the tablets will be too heavy and bulky, causing certain difficulties for patients to swallow the medicine, reducing the compliance of patients with the medicine, and not conducive to the treatment of the disease. However, the acetaminophen content in acetaminophen tablets is generally required to be more than 85%, and acetaminophen has poor compressibility, high content, small space for auxiliary materials, and is easily hydrolyzed into acetaminophen in a humid environment. How to reduce the weight of acetaminophen tablets is a challenge to the preparation process of acetaminophen tablets.

[0004] The original reference preparation of acetaminophen tablets (0.5g) announced by the National Medical Products Administration is produced by GlaxoSmithKline Consumer Healthcare and supplied to the global market. The tablet core prescription composition is: acetaminophen, corn starch, pregelatinized starch, potassium sorbate, povidone, stearic acid, and talc.

[0005] Chinese patent document CN110496107A discloses an acetaminophen tablet and a preparation method thereof. The acetaminophen tablet is composed of the following raw materials in parts by weight: 1100-12500 parts of acetaminophen, 46-50 parts of povidone K30, 160-176 parts of purified water, 120-136 parts of pregelatinized starch, 9.1-9.9 parts of stearic acid and 2.9-3.5 parts of magnesium stearate; the preparation method uses stearic acid and magnesium stearate as lubricants, but the mixing time is 25 minutes. Too long a mixing time will cause excessive mixing of magnesium stearate, which will easily lead to problems such as tablet cracking and decreased solubility of the product; Chinese patent document CN108853038A discloses a paracetamol tablet and a preparation process thereof, which comprises the following steps: adding potassium sorbate to purified water to dissolve to obtain a potassium sorbate solution; adding paracetamol, pregelatinized starch, calcium carbonate, povidone K30, and cross-linked povidone to a high-efficiency wet granulator for premixing for 3 minutes; adding the potassium sorbate solution to the premixed powder, and continuing to stir for 2 minutes to obtain wet granules; placing the wet granules in a boiling granulation dryer for drying, controlling the drying temperature to 90-100°C, and drying to a water content of 1-3% to obtain granules; granulating the dry granules to obtain 16-mesh granules; placing the granules in a mixer, adding seaweed Acid, silicon dioxide and magnesium stearate are sealed and mixed for 20 minutes, and the speed of the mixer is set to 10 rpm; the mixed particles are tableted and sieved; the prescription is relatively complicated, involving many types of auxiliary materials and large amounts, the main drug accounts for a relatively low proportion, the tablets are large, and each tablet weighs 669 mg, which brings certain inconveniences to patients and reduces patients' compliance with medication; Chinese patent document CN114129524A discloses a paracetamol tablet and a preparation method thereof, wherein the tablet contains paracetamol, a binder, a disintegrant and a lubricant, and the preparation method is: dry-mixing the paracetamol raw material with the binder and part of the disintegrant, adding The product is granulated in water, and the remaining disintegrant and lubricant are added after drying. The whole granules are mixed and tablets are obtained. The preparation process has the following problems: acetaminophen crystals are brittle and crushable materials with typical molar compression characteristics. They are in the form of long needle-shaped crystals, have great brittleness, weak plastic deformation ability, and poor compressibility. The preparation process uses acetaminophen raw materials, adhesives and part of disintegrants for dry mixing. Due to the small amount of adhesive used, there may be problems with mixing uniformity in the dry mixing step. The process of adding water for granulation may not fully induce the adhesive properties of the adhesive, resulting in problems such as "splitting" or "cap falling off" in the subsequent tableting process, affecting the quality of the product.Therefore, although these existing technologies can solve the problems of poor material compressibility and quality inconsistency with the original preparation during the preparation of acetaminophen tablets, the prescription composition is complex, the preparation process is cumbersome, and it is not suitable for industrial production. In addition, the main drug accounts for a low proportion, and the tablets are large, causing trouble for patients to swallow. The use of ethanol solvents may cause problems such as solvent residues, or surfactants that do not meet the scope of BE exemption for generic drug consistency evaluation are used. Summary of the invention

[0006] In view of the problems existing in the prior art, the present invention provides an acetaminophen tablet and a preparation method thereof. The drug prescription composition is simple, the types and amounts of auxiliary materials are small, the main drug accounts for a high proportion, and the tablet weight is small, which can improve the patient's compliance with medication. In addition, the product quality is stable, the dissolution is complete, and the quality is consistent with the original preparation, thereby ensuring the therapeutic effect of the acetaminophen tablet.

[0007] The invention provides a paracetamol tablet. The tablet contains 86.88 parts of paracetamol, 4.52 parts of a binder, 2.90 parts of a disintegrant, 5.21 parts of a filler and 0.49 parts of a lubricant in percentage by mass.

[0008] Furthermore, the adhesive is pregelatinized starch and povidone, and the weight ratio of the two is 6:20.

[0009] Furthermore, the disintegrant and filler are both pregelatinized starch.

[0010] Furthermore, the lubricant is magnesium stearate.

[0011] The present invention also provides a method for preparing acetaminophen tablets, comprising the following preparation steps:

[0012] S1. Crush acetaminophen;

[0013] S2. Weigh acetaminophen and filler and set aside;

[0014] S3, drying the disintegrant for later use;

[0015] S4, mixing the binder and water evenly to obtain a mixed slurry for standby use;

[0016] S5, adding the acetaminophen and filler obtained in step S2 into a wet granulator and stirring and mixing;

[0017] S6, then adding the mixed slurry obtained in step S4, stirring, granulating, and obtaining wet granules;

[0018] S7, drying the wet granules;

[0019] S8, adding the disintegrant obtained in step S3 to the dried granules, mixing them in a mixer, and then adding a lubricant to mix them;

[0020] S9. Use a tablet press to compress the mixed granules into tablets to obtain acetaminophen tablets.

[0021] Furthermore, the drying in step S3 is to place the disintegrant in a boiling granulator and dry it at 80-90° C. until the moisture content is 2-4%.

[0022] Furthermore, the stirring in step S4 is to weigh purified water and pregelatinized starch and stir them evenly to obtain pregelatinized starch slurry; take purified water and povidone and stir them evenly to obtain povidone slurry, and then mix the pregelatinized starch slurry and povidone slurry and stir them evenly to obtain a mixed slurry.

[0023] Furthermore, the granulation time in step S6 is 30 to 60 seconds.

[0024] Furthermore, the drying operation in step S7 is to dry the particles at an inlet air temperature of 80° C. until the moisture content of the particles is 1.8-2.8%.

[0025] Furthermore, the total mixing time in step S8 is 5 minutes.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. The present invention improves the formula of acetaminophen tablets. The drug prescription composition is simple, the types and amounts of excipients are small, the main drug accounts for a high proportion, and the tablet weight is small, which can minimize the management and inspection costs of excipients and improve patients' compliance with medication. In addition, the product quality is stable, the dissolution is complete, the quality is consistent with the original preparation, and it does not contain surfactants, which meets the BE exemption requirements for the consistency evaluation of generic drugs.

[0028] 2. The preparation process of the acetaminophen tablets provided by the present invention has the advantages of simple process, low production cost, safe production, no need for boiling water or organic solvent slurry preparation, high degree of mechanization, suitability for industrial production, and solving the problem of poor compressibility of acetaminophen tablets.

[0029] 3. The present invention fully exploits the performance of the conventional auxiliary material pregelatinized starch, so that it plays four roles of filler, binder, disintegrant and stabilizer in the present prescription, and has the effect of reducing water activity. The pregelatinized starch dried to 2-4% moisture at 80-90°C in a boiling granulator can re-absorb the residual trace moisture in the acetaminophen tablets, play the role of stabilizer and prevent its degradation.

[0030] 4. The acetaminophen tablets provided by the present invention are different from the original acetaminophen tablets (specification 0.5 g, trade name ) have the same in vitro dissolution behavior, the dissolution curve similarity factor f2 is greater than 50, and they have the same therapeutic effect. DETAILED DESCRIPTION

[0031] The experimental methods in the following examples of the present invention without specifying specific conditions are usually carried out under conventional conditions or under conditions recommended by the manufacturer. The various commonly used pharmaceutical excipients used in the examples are all commercially available products.

[0032] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0033] 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 specific embodiments. It should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0034] The present invention is further described in the following examples, but the examples are not intended to limit the scope of protection of the present invention.

[0035] Example 1: Acetaminophen tablets of the present invention and preparation thereof

[0036] The acetaminophen tablet prescription (1000 tablets dosage) of the present embodiment is as follows:

[0037] Table 1. Prescription of acetaminophen tablets (dosage for 1000 tablets)

[0038] Components Element Dosage content Main drug Acetaminophen 500.0g 86.88％ Fillers Pregelatinized starch 30.0g 5.21％ Disintegrants Pregelatinized starch 16.7g 2.90％ Adhesives Pregelatinized starch 6.0g 1.04％ Adhesives Povidone 20.0g 3.48％ Lubricants Magnesium Stearate 2.8g 0.49％

[0039] The preparation method of acetaminophen tablets comprises the following steps:

[0040] S1. Crush acetaminophen;

[0041] S2, weigh 500.0 g of acetaminophen and 30.0 g of pregelatinized starch, set aside;

[0042] S3, 16.7 g of pregelatinized starch was placed in a boiling granulator and dried at 80° C. to a moisture content of 4%, and set aside;

[0043] S4, weigh 54.0 g of purified water, add 6.0 g of pregelatinized starch, stir evenly to obtain pregelatinized starch slurry; take 60.0 g of purified water, add 20.0 g of povidone, stir evenly to obtain povidone slurry; mix the pregelatinized starch slurry and povidone slurry and stir evenly to obtain 140.0 g of mixed slurry for standby use;

[0044] S5, adding the acetaminophen and pregelatinized starch of step S2 into a wet granulator, stirring at 180 rpm, chopping at 1800 rpm, and mixing for 10 min;

[0045] S6, then add the mixed slurry obtained in step S4, stir at 180 rpm, chop at 1800 rpm, and granulate for 30 seconds to obtain wet granules;

[0046] S7, placing the wet granules in a boiling granulator with an inlet air temperature of 80°C and drying the granules until the moisture content is 1.8%;

[0047] S8, adding the pregelatinized starch obtained in step S3 to the dried granules, placing in a mixer and mixing for 5 minutes, and then adding 2.8 g of magnesium stearate and mixing for 5 minutes;

[0048] S9. The mixed granules are compressed into tablets using a tablet press to obtain acetaminophen tablets with a tablet weight of 575.5 mg.

[0049] Example 2: Paracetamol tablets of the present invention and preparation thereof

[0050] The prescription of the acetaminophen tablets of the present embodiment (10,000 tablets) is as follows:

[0051] Table 2. Prescription of acetaminophen tablets (10,000 tablets)

[0052] Components Element Dosage content Main drug Acetaminophen 5.00kg 86.88％ Fillers Pregelatinized starch 0.3kg 5.21％ Adhesives Pregelatinized starch 0.06kg 1.04％ Disintegrants Pregelatinized starch 0.167kg 2.90％ Adhesives Povidone 0.2kg 3.48％ Lubricants Magnesium Stearate 0.028kg 0.49％

[0053] The preparation method of acetaminophen tablets comprises the following steps:

[0054] S1. Crush acetaminophen;

[0055] S2, weigh 5 kg of acetaminophen and 0.3 kg of pregelatinized starch, set aside;

[0056] S3, placing 0.167 kg of pregelatinized starch in a boiling granulator and drying it at 85° C. to 3% moisture, and set aside;

[0057] S4, weigh 0.54 kg of purified water, add 0.06 kg of pregelatinized starch, stir evenly to obtain pregelatinized starch slurry; take 0.6 kg of purified water, add 0.2 kg of povidone, stir evenly to obtain povidone slurry; mix the pregelatinized starch slurry and povidone slurry and stir evenly to obtain 1.4 kg of mixed slurry for standby use;

[0058] S5, adding the acetaminophen and pregelatinized starch obtained in step S2 into a wet granulator, stirring at 180 rpm, chopping at 1800 rpm, and mixing for 10 min;

[0059] S6, then add 1.400 kg of the mixed slurry obtained in step S4, stir at 180 rpm, chop at 1800 rpm, and granulate for 45 seconds to obtain wet granules;

[0060] S7, placing the wet granules in a boiling granulator and drying them at an inlet air temperature of 80°C until the moisture content of the granules reaches 2.3%;

[0061] S8, adding the dried granules to the pregelatinized starch obtained in step S3 and mixing in a mixer for 5 minutes, and then adding 0.028 kg of magnesium stearate and mixing for 5 minutes;

[0062] S9. The mixed granules are compressed into tablets using a tablet press to obtain acetaminophen tablets with a tablet weight of 575.5 mg.

[0063] Example 3: Acetaminophen tablets of the present invention and preparation thereof

[0064] The prescription of the acetaminophen tablets of the present embodiment (consumption of 100,000 tablets) is as follows in Table 3:

[0065] Table 3. Prescription of acetaminophen tablets (100,000 tablets)

[0066] Components Element Dosage content Main drug Acetaminophen 50.00kg 86.88％ Fillers Pregelatinized starch 3.00kg 5.21％ Adhesives Pregelatinized starch 0.60kg 1.04％ Disintegrants Pregelatinized starch 1.67kg 2.90％ Adhesives Povidone 2.00kg 3.48％ Lubricants Magnesium Stearate 0.28kg 0.49％

[0067] The preparation method of acetaminophen tablets comprises the following steps:

[0068] S1. Crush acetaminophen;

[0069] S2, weigh 50.00 kg of acetaminophen and 3.00 kg of pregelatinized starch, set aside;

[0070] S3, 1.67 kg of pregelatinized starch was placed in a boiling granulator and dried at 90° C. to a moisture content of 2%, and set aside;

[0071] S4, weigh 5.40 kg of purified water, add 0.60 kg of pregelatinized starch, stir evenly to obtain pregelatinized starch slurry; take 6.00 kg of purified water, add 2.00 kg of povidone, stir evenly to obtain povidone slurry; mix the pregelatinized starch slurry and the povidone slurry and stir evenly to obtain 14.00 kg of mixed slurry for standby use;

[0072] S5, adding the acetaminophen and pregelatinized starch obtained in step S2 into a wet granulator, stirring at 180 rpm, chopping at 1800 rpm, and mixing for 10 min;

[0073] S6, then add 14.00 kg of the mixed slurry obtained in step S4, stir at 180 rpm, chop at 1800 rpm, and granulate for 60 seconds to obtain wet granules;

[0074] S7, placing the wet granules in a boiling granulator and drying them at an inlet air temperature of 80°C until the moisture content of the granules reaches 2.8%;

[0075] S8, adding the dried granules to the pregelatinized starch obtained in step S3 and mixing in a mixer for 5 minutes, and then adding 0.28 kg of magnesium stearate and mixing for 5 minutes;

[0076] S9. The mixed granules are compressed into tablets using a tablet press to obtain acetaminophen tablets with a tablet weight of 575.5 mg.

[0077] Comparative Example 1

[0078] The only difference between this comparative example and Example 1 is that the disintegrant is not dried; that is, the preparation process of acetaminophen tablets is:

[0079] S1. Crush acetaminophen;

[0080] S2, weigh 50.00 kg of acetaminophen and 3.00 kg of pregelatinized starch, set aside;

[0081] S3, weigh 5.40 kg of purified water, add 0.60 kg of pregelatinized starch, stir evenly to obtain pregelatinized starch slurry; take 6.00 kg of purified water, add 2.00 kg of povidone, stir evenly to obtain povidone slurry; mix the pregelatinized starch slurry and the povidone slurry and stir evenly to obtain 14.00 kg of mixed slurry for standby use;

[0082] S4, adding the acetaminophen and pregelatinized starch obtained in step S2 into a wet granulator, stirring at 180 rpm, chopping at 1800 rpm, and mixing for 10 min;

[0083] S5, then add 14.00 kg of the mixed slurry obtained in step S3, stir at 180 rpm, chop at 1800 rpm, and granulate for 30 seconds to obtain wet granules;

[0084] S6, placing the wet granules in a boiling granulator and drying them at an inlet air temperature of 80°C until the moisture content of the granules reaches 1.8%;

[0085] S7, adding 1.67 kg of pregelatinized starch to the dried granules and mixing them in a mixer for 5 min, and then adding 0.28 kg of magnesium stearate and mixing them for 5 min;

[0086] S8. The mixed granules are compressed into tablets using a tablet press to obtain acetaminophen tablets with a tablet weight of 575.5 mg.

[0087] Comparative Example 2

[0088] The only difference between this comparative example and Example 1 is that step S4 in the preparation process is changed, and the adhesive pregelatinized starch and povidone are not stirred with water separately and then mixed together, but are directly mixed with water, that is, step S4 is: weigh 114.0 g of purified water, add 6.0 g of pregelatinized starch and 20.0 g of povidone, stir evenly, and obtain 140.0 g of mixed slurry for standby use.

[0089] Comparative Example 3

[0090] The original drug acetaminophen tablets produced by GlaxoSmithKline Consumer Healthcare, specification 0.5g, trade name

[0091] Test Example 1: Dissolution Study of Acetaminophen Tablets

[0092] 1. Test sample: acetaminophen tablets prepared in Examples 1-3 and Comparative Examples 1-3;

[0093] 2. Test method: According to the first method of 0931 of the fourth general rule of the 2020 edition of the Chinese Pharmacopoeia, the dissolution medium is a dilute hydrochloric acid solution (accurately measure 24 mL of dilute hydrochloric acid and add water to 1000 mL), and the dissolution of the acetaminophen tablets prepared in Examples 1-3 and Comparative Examples 1-3 is measured at 5 min, 10 min, 15 min and 30 min;

[0094] 3. Test results, see Table 4 below;

[0095] Table 4. Dissolution values ​​of acetaminophen tablets

[0096]

[0097] As shown in Table 4, the acetaminophen tablets prepared in Examples 1-3 of the present invention are different from the acetaminophen tablets (specification 0.5 g, trade name ) have the same in vitro dissolution behavior, and the dissolution rate at 15min is greater than 85%. Since the acetaminophen tablets are BE exemption varieties for the consistency evaluation of generic drugs, and the acetaminophen tablets are immediate-release preparations, the 15min dissolution rate is greater than 85%, and there is no need to compare the dissolution curve similarity factor f2, indicating that the acetaminophen tablets prepared in Examples 1-3 of the present invention and the original research drug acetaminophen tablets produced by GlaxoSmithKline Consumer Healthcare in Comparative Example 3 have the same therapeutic effect. In Comparative Example 1, since the disintegrant is not placed in a boiling granulator at 80-90°C and dried to 2-4% moisture, the dissolution rate is relatively slow. The reason is that the disintegration ability of the pregelatinized starch after drying will be greatly enhanced, which improves the dissolution rate of the preparation. The pregelatinized starch in Comparative Example 1 that has not been dried has a weak disintegration ability and a slow dissolution rate. In Comparative Example 2, step S4 in the preparation process is changed. The binders pregelatinized starch and povidone are not stirred with water separately and then mixed together, but are directly mixed with water. Although the solubility of the acetaminophen tablets prepared by this method is basically unchanged, the binder is difficult to be completely dissolved and dispersed when prepared by this method, so that the tablets are prone to "cracks" during tableting.

[0098] Test Example 2: Inspection of the tableting pass rate of acetaminophen tablets

[0099] 1. Test sample: acetaminophen tablets prepared in Examples 1-3 and Comparative Examples 1-2;

[0100] 2. Test method: Calculate the qualified rate of batch output tableting based on the ratio of qualified product output to the material receiving quantity;

[0101] 3. Judgment criteria: The one with smooth surface, no cracks or loose pieces is considered qualified;

[0102] 4. Test results:

[0103] Table 5. Tablet pass rate of acetaminophen tablets

[0104]

[0105]

[0106] As can be seen from Table 5, the acetaminophen tablets prepared in Examples 1-3 of the present invention have smooth surfaces, no cracking or loosening, and the tableting qualified rate reaches 100%, indicating that the preparation method of the acetaminophen tablets provided by the present invention solves the problem of poor compressibility of the acetaminophen tablets, and has a simple process, low production cost, safe production, high degree of mechanization, and is suitable for industrial production; while the tableting qualified rate of Comparative Example 1 also reaches 100%, but the dissolution rate will be slow, because the disintegrant of Comparative Example 1 is not placed in a boiling granulator to dry to 2-4% moisture at 80-90° C., and the pregelatinized starch that has not been dried has weak disintegration ability, which will lead to slow dissolution of the preparation; and the tableting qualified rate of the acetaminophen tablets prepared in Comparative Example 2 is only 94.2%, because the preparation process of Comparative Example 2 has changed, which has affected the stability of the acetaminophen tablets, resulting in poor compressibility of the acetaminophen tablets.

[0107] Test Example 3: Stability Study of Acetaminophen Tablets

[0108] 1. Test sample: acetaminophen tablets prepared in Examples 1-3 and Comparative Examples 1-2;

[0109] 2. Test method: Place in a stability test chamber at 40°C and 70%, and take out at 0 day, 1 month, 3 months, and 6 months for in vitro dissolution determination;

[0110] 3. Test results:

[0111] Table 6. Stability study data of acetaminophen tablets

[0112] Group Day 0 January March June Example 1 100.2％ 99.6％ 99.7％ 99.8％ Example 2 99.9％ 99.7％ 99.8％ 99.7％ Example 3 99.7％ 99.4％ 99.6％ 99.5％ Comparative Example 1 90.4％ 86.2％ 84.2％ 81.4％ Comparative Example 2 99.3％ 99.2％ 99.1％ 99.0％

[0113] As can be seen from Table 6, the in vitro dissolution of the acetaminophen tablets prepared in Examples 1-3 after being subjected to a high temperature and high humidity environment of 40°C and 70% for 1 month, 3 months and 6 months is higher than that of the acetaminophen tablets prepared in Comparative Examples 1-3, and the in vitro dissolution changes for 1 month, 3 months and 6 months are not obvious, while the in vitro dissolution of the acetaminophen tablets prepared in Comparative Example 1 shows a significant downward trend. This is because the pregelatinized starch, a disintegrant in Comparative Example 1, has not been subjected to the operation of being placed in a boiling granulator at 80-90°C and dried to a moisture content of 2-4%, and the pregelatinized starch after the drying operation is used as a disintegrant to prepare acetaminophen tablets, which can accelerate the disintegration rate of acetaminophen tablets and improve the dissolution rate; although the in vitro dissolution of Comparative Example 2 does not decrease significantly, the tableting qualification rate is low.

[0114] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A paracetamol tablet, characterized in that: In terms of mass percentage, the tablet contains 86.88 parts of acetaminophen, 4.52 parts of a binder, 2.90 parts of a disintegrant, 5.21 parts of a filler and 0.49 parts of a lubricant; The adhesive is pregelatinized starch and polyvidone, and the weight ratio of the two is 6:20; The disintegrant and filler are both pregelatinized starch; The lubricant is magnesium stearate; The preparation method of the acetaminophen tablets comprises the following preparation steps: S1. Crush acetaminophen; S2. Weigh acetaminophen and filler and set aside; S3, drying the disintegrant for later use; S4, mixing the binder and water evenly to obtain a mixed slurry for standby use; S5, adding the acetaminophen and filler obtained in step S2 into a wet granulator and stirring and mixing; S6, adding the mixed slurry obtained in step S4, stirring, granulating, and obtaining wet granules; S7, drying the wet granules; S8, adding the dried granules to the disintegrant obtained in step S3, mixing in a mixer, and then adding a lubricant to mix; S9, compressing the mixed granules into tablets using a tablet press to obtain acetaminophen tablets; The drying in step S3 is to place the disintegrant in a boiling granulator and dry it at 80-90° C. to a moisture content of 2-4%; The stirring in step S4 is to evenly stir purified water and pregelatinized starch to obtain pregelatinized starch slurry; to evenly stir purified water and povidone to obtain povidone slurry, and then to evenly mix the pregelatinized starch slurry and povidone slurry to obtain a mixed slurry.

2. The method for preparing acetaminophen tablets according to claim 1, wherein The granulation time in step S6 is 30 to 60 seconds.

3. The method for preparing acetaminophen tablets according to claim 1, characterized in that: The drying operation in step S7 is to dry the particles at an inlet air temperature of 80° C. until the moisture content of the particles is 1.8-2.8%.

4. The method for preparing acetaminophen tablets according to claim 1, characterized in that: The total mixing time in step S8 is 5 minutes.

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