A medicament for neuralgia and a method for preparing the same

Abstract

This invention discloses a neuropathic pain drug and its preparation method, relating to the field of traditional Chinese medicine preparation technology. The method includes pulverizing and sieving wild papaya dry extract to obtain dry extract powder, then premixing it with hydrophobic excipients in a mixer to uniformly coat the surface of the dry extract powder particles and form a hydrophobic isolation layer, resulting in a premixed coated material. The premixed coated material is then mixed with starch, and starch slurry is added to form a soft mass. After granulation, drying, and sizing, a lubricant is added for final mixing, tableting, and coating to obtain the neuropathic pain drug. This invention reduces the hygroscopicity of wild papaya dry extract powder by adding a hydrophobic excipient premixing and coating process before granulation of the dry extract powder and starch. This overcomes the process and quality problems caused by strong hygroscopicity, such as sticky granulation, tablet sticking, and slow disintegration during storage. The resulting neuropathic pain drug maintains stable disintegration performance and appearance quality even in humid environments, and the process is simple.

Description

Technical Field

[0001] This invention relates to the field of traditional Chinese medicine preparation technology, specifically to a neuropathic pain drug and its preparation method. Background Technology

[0002] Neuropathic pain medications, such as wild papaya tablets, are traditional Chinese medicine preparations, listed in drug standard WS3-B-2777-97-2. They are made by extracting, concentrating, and drying wild papaya into a dry extract, then granulating with starch, compressing, and coating. Each tablet contains 0.4g of wild papaya dry extract, with the extract accounting for over 90% of the tablet core weight. Clinically, this product is used to dispel wind and relieve pain, relax muscles and tendons, and is suitable for trigeminal neuralgia, sciatica, and rheumatic joint pain caused by wind-evil obstructing the meridians.

[0003] Currently, the preparation of neuralgia medication (wild papaya tablets) mainly follows this standard: Wild papaya is chopped, decocted twice with water for 2 hours each time, the decoctions are combined, filtered, the filtrate is concentrated into a thick paste, dried into a dry extract, granulated with an appropriate amount of starch, compressed into tablets, and coated. In this process, the dry extract is directly mixed with starch and granulated after being pulverized, without pretreatment to address the hygroscopicity of the dry extract powder. Existing technologies have explored the hygroscopicity issue of traditional Chinese medicine extract preparations. For example, patent publication number CN1943787A discloses a drug moisture-proof composition, which is a mixture of diluent excipients (such as lactose, acrylic resin, etc.) and lubricant excipients (such as magnesium stearate, talc, etc.). This composition adds moisture-proof excipients as a mixture to the extract powder to reduce the hygroscopicity of the preparation. For example, in the study of the moisture-proof molding process of Yangxue Danggui tablets, 0.5% magnesium stearate was added as a lubricant during the final mixing stage after granulation to improve the flowability and formability of the particles. In the above schemes, magnesium stearate was added after simple mixing with other excipients, or as a lubricant after granulation. Magnesium stearate coexisted with other excipients and did not form a selective coating on the dry extract powder particles.

[0004] However, wild papaya dry extract is rich in polar components such as polysaccharides and saponins, making it highly hygroscopic. None of the existing technologies mentioned above offer an effective solution to the hygroscopic characteristics of neuropathic pain medications. Neuropathic pain medications prepared using existing processes are prone to absorbing moisture during storage and granulation, leading to high stickiness of the soft material during granulation, difficulty in drying the granules, sticking during tableting, and slow disintegration or even mold growth of the finished product after moisture absorption during storage, directly affecting product quality and shelf life.

[0005] In summary, existing preparation processes and moisture-proof technologies for neuropathic pain medications (wild papaya tablets) have failed to effectively address the process and quality issues caused by the hygroscopicity of wild papaya dried extract powder. Therefore, it is necessary to provide a method for preparing neuropathic pain medications that can effectively reduce the hygroscopicity of wild papaya dried extract powder and improve the granulation and tableting process performance. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a neuropathic pain drug and its preparation method. By adding a hydrophobic excipient premixing and coating process after the wild papaya dry extract is pulverized and before it is mixed with starch for granulation, hydrophobic excipients such as magnesium stearate are used to form a hydrophobic isolation layer on the surface of the dry extract powder particles, thereby reducing the hygroscopicity of the dry extract powder, improving the granulation and tableting process performance, and improving the quality stability of the neuropathic pain drug.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: In one aspect, a method for preparing a neuropathic pain drug, the method comprising the following steps: S1, crush the dried wild papaya extract through an 80-mesh sieve to obtain dried wild papaya extract powder; S2, add wild papaya dried extract powder and 3%-8% of hydrophobic excipients by weight of wild papaya dried extract powder into a mixer, premix for 15-30 minutes at room temperature, so that the hydrophobic excipients coat the surface of wild papaya dried extract powder particles to obtain premixed coated material. S3, mix the premixed coating material with starch, add 10% starch slurry to make a soft material, and then granulate, dry, sizing, mix, compress and coat in sequence to obtain the neuralgia drug; The hygroscopicity of the dry extract powder is reduced by forming a hydrophobic barrier layer on the surface of the dry extract powder particles through hydrophobic excipients.

[0008] Furthermore, in step S2, the hydrophobic excipient is one or more of magnesium stearate, micronized silica gel, and talc. Magnesium stearate, micronized silica gel, and talc are all hydrophobic excipients listed in the pharmacopoeia and have good hydrophobicity and safety.

[0009] Furthermore, in S2, the hydrophobic excipient is magnesium stearate, and the amount of magnesium stearate is 5% of the weight of wild papaya dried extract powder. When magnesium stearate is used as a coating excipient, the coating uniformity is best when the amount is controlled at 5% and it does not affect the subsequent tablet disintegration.

[0010] Furthermore, in S2, the speed of the mixer is 10-30 r / min.

[0011] Furthermore, the mixer operates at a speed of 20 r / min, and the premixing time is 20 min.

[0012] Furthermore, in S1, the dried wild papaya extract is prepared by the following method: Cut the wild papaya into sections, add water and decoct twice, 2 hours each time. Combine the decoctions, filter, concentrate the filtrate to a relative density of 1.30-1.35, heat at 80℃ to obtain a thick paste, dry the paste until the moisture content does not exceed 3% to obtain wild papaya dry extract.

[0013] Furthermore, in step S3, the soft material is granulated by passing it through a 14-mesh sieve; The dried granules are sieved through a 14-mesh sieve for granulation. Granulation and sizing are performed using a 14-mesh sieve, resulting in uniform particle size, which is beneficial for controlling tablet weight in subsequent tableting processes.

[0014] Furthermore, in step S3, the wet particles are dried at 75-80°C until the particle moisture content is 3%-5%; Maintaining the moisture content of the granules at 3%-5% ensures good flowability and compressibility while preventing excessive moisture from causing the tablets to stick together during compression.

[0015] Furthermore, in step S3, magnesium stearate is added for total mixing, and the amount of magnesium stearate added is 0.5% of the weight of the granulated particles.

[0016] On the other hand, a neuropathic pain drug is applicable to a method for preparing a neuropathic pain drug, wherein the neuropathic pain drug is prepared by the method, and the surface of the dry extract powder particles prepared by the above method has a hydrophobic isolation layer, the hygroscopicity of the tablets is significantly reduced, and the storage stability is improved.

[0017] Compared with existing technologies, this neuropathic pain drug and its preparation method have the following beneficial effects: I. This invention premixes and encapsulates wild papaya dry extract powder with hydrophobic excipients, constructing a hydrophobic isolation layer on the granule surface. This blocks the contact between water and the hydrophilic components in the extract, effectively reducing the hygroscopicity of the dry extract powder. Consequently, the soft material viscosity is moderate during the granulation process, sieving is smooth, there is no sticking or snagging during tableting, and the tablets have an intact appearance. The moisture absorption rate of the finished product is significantly slowed down during storage, avoiding slow disintegration or even mold growth caused by moisture absorption, ensuring the quality stability of the drug and the safety of clinical use within its shelf life.

[0018] Second, this invention improves the utilization efficiency of hydrophobic excipients through selective encapsulation, achieving good moisture-proof effects with a smaller amount of excipients. It does not increase tablet weight or cause disintegration obstacles due to excessive excipients. The encapsulation layer is on the surface of the particles and does not block the internal pores of the tablets, allowing the disintegrant to still exert its swelling effect normally. The tablets can maintain a shorter disintegration time. At the same time, the premixed encapsulation improves the flowability of the dry extract powder, which is beneficial for the stable control of tablet weight differences during the tableting stage. This process only adds one step of room temperature mixing operation. The equipment is universal and highly compatible with existing Chinese medicine tablet production lines. The process modification is small, easy to implement industrially, and basically does not increase production costs.

[0019] Other advantages, objectives and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination or study, or may be learned from the practice of the invention. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0021] Figure 1 This is a flowchart of the preparation process of the present invention. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0023] In the description of this invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Furthermore, the technical features involved in the different embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0025] This embodiment provides a neuropathic pain drug and its preparation method. The method adds a hydrophobic excipient pre-mixing and coating process after the wild papaya dry extract is pulverized and before it is mixed with starch for granulation. This addresses problems such as granulation stickiness, tablet sticking, and slow disintegration of the finished product during storage due to the high hygroscopicity of the dry extract powder. The preparation process is as follows: Figure 1As shown, the process sequentially includes obtaining dried wild papaya extract, crushing and sieving in step S1, premixing and coating with hydrophobic excipients in step S2, and mixing with starch to form a soft mass, granulation, drying, sizing, mixing, tableting, and coating in step S3. The specific implementation methods for each step are described in detail below.

[0026] First, prepare the dried extract of wild papaya. Take the cleaned wild papaya medicinal material, cut it into 1cm-2cm segments, and put it into a multi-functional extraction tank. Add 8-10 times the amount of water for the first time, heat to boiling, and maintain a gentle boil for 2 hours, stirring occasionally during the extraction process. Discard the decoction, add 6-8 times the amount of water to the residue, and decoct again for 2 hours using the same method. Combine the two decoctions, filter while hot through a 200-mesh filter cloth, and transfer the filtrate to a double-effect concentrator. Concentrate at a temperature of 70℃-80℃ and a vacuum degree of -0.06MPa---0.08MPa until the relative density of the concentrate reaches 1.30-1.35 when measured at 80℃, forming a thick paste. Place the thick paste in a vacuum drying oven at a temperature of 65℃-75℃ and a vacuum degree of -0.08MPa---0.09MPa until the moisture content does not exceed 3%. Remove and cool to obtain the dried extract of wild papaya. The dry extract is a brownish-red, hard, and brittle substance with a slightly bitter taste and strong hygroscopic properties.

[0027] Step S1: The dried wild papaya extract is pulverized and passed through an 80-mesh sieve to obtain dried wild papaya extract powder. Specifically, a universal pulverizer equipped with a water-cooled jacket is used to pulverize the dried extract blocks, and the relative humidity of the operating environment is controlled below 45%. The pulverized material is collected and sieved through an 80-mesh vibrating sieve. The portion passing through the sieve is the dried wild papaya extract powder; the coarse powder that does not pass through the sieve is returned to the pulverizer for further pulverization until all of it passes through the sieve. Throughout the pulverization process, attention must be paid to the temperature rise of the material to avoid overheating and softening of the extract. The obtained dried wild papaya extract powder is a brownish-brown fine powder. It absorbs moisture and sticks to the walls after a short exposure to air, indicating that it has strong hygroscopic properties, which would pose significant challenges if directly introduced into the subsequent granulation process.

[0028] Step S2 involves premixing and coating the dried wild papaya extract powder obtained in step S1 with a hydrophobic excipient, forming a hydrophobic isolation layer on the surface of the dried extract powder particles. This step is a crucial step in the entire preparation method. The hydrophobic excipient is selected from one or more of magnesium stearate, micronized silica gel, and talc listed in the pharmacopoeia, and its total amount is 3%-8% of the weight of the dried wild papaya extract powder.

[0029] In a preferred embodiment, magnesium stearate is used as the hydrophobic excipient, at a dosage of 5% of the weight of the dried wild papaya extract powder. Magnesium stearate is a white, loose powder with a large specific surface area, exhibiting good hydrophobicity and adhesion. During operation, 1000g of dried wild papaya extract powder and 50g of magnesium stearate are weighed and added together to the drum of a three-dimensional motion mixer. After sealing, the mixer speed is set to 20 rpm, and mixing is carried out at room temperature for 20 minutes. During the mixing process, the drum undergoes three-dimensional spatial motion, and the material continuously diffuses, convections, and shears within the drum. The magnesium stearate particles gradually adsorb and spread onto the surface of the dried extract powder particles, forming a basically continuous hydrophobic coating film. After mixing, the material is discharged, yielding the pre-mixed coated material. This material has a uniform appearance, a slightly lighter color than before coating, and a smooth feel. After being placed in an environment with a relative humidity of 60% for 1 hour, no moisture absorption or clumping is observed. The hydrophobic barrier layer serves to physically isolate the polar groups of hydrophilic components such as polysaccharides and saponins in the dry extract powder from external moisture, thereby reducing the driving force for moisture absorption of the powder from the source.

[0030] In another embodiment, the hydrophobic excipient is a combination of magnesium stearate and micronized silica gel, with a total amount of 5% of the dry extract powder weight, of which magnesium stearate accounts for 3% and micronized silica gel accounts for 2%. Micronized silica gel is lightweight and has a larger specific surface area, which can help magnesium stearate form a denser hydrophobic layer and improve the flowability of the powder. 1000g of wild papaya dry extract powder, 30g of magnesium stearate, and 20g of micronized silica gel are added to a V-type mixer, and the speed is set to 10r / min for 30min. Since the bulk density of micronized silica gel is very low, the mixing time is appropriately extended to ensure that it fully adheres to the surface of the dry extract powder particles. The resulting premixed coated material is loose, and the angle of repose is reduced from about 48° when uncoated to 38°, with a significant improvement in flowability.

[0031] In another embodiment, the hydrophobic excipient is talc powder alone, used at 8% of the weight of the dry extract powder. The talc powder is hydrated magnesium silicate, possessing a layered structure and hydrophobicity. 1000g of the dry extract powder and 80g of talc powder are added together to a three-dimensional mixer at a speed of 15 rpm for 25 minutes to obtain a premixed coated material. Talc powder has a higher density than magnesium stearate; appropriately reducing the speed can prevent stratification. This method is cost-effective and can form an effective hydrophobic barrier layer.

[0032] To verify the effect of premixed coating on reducing hygroscopicity, a comparative study of hygroscopicity was conducted. Uncoated wild papaya dry extract powder, the material coated with 5% magnesium stearate, the material coated with a combination of magnesium stearate and micronized silica gel, and the material coated with 8% talc were placed in sealed containers at 75% relative humidity. After 24 hours, their moisture absorption weight gain percentage was measured. The moisture absorption rate of the uncoated dry extract powder reached 15.0%; the moisture absorption rate of the material coated with 5% magnesium stearate was 7.5%, a reduction of 50%; the moisture absorption rate of the combined coated material was 7.9%; and the moisture absorption rate of the material coated with 8% talc was 9.6%.

[0033] After completing the premixed coating in step S2, proceed to step S3. Step S3 includes mixing the premixed coating material with starch, preparing a soft mass, granulating, drying, sizing, mixing, tableting, and coating to finally obtain the neuropathic pain medication.

[0034] The specific steps are as follows: First, the premixed coating material obtained in step S2 is mixed with starch. Starch serves as a disintegrant and filler in the formulation. Assuming each tablet contains 0.4g of wild papaya dry extract and a target core weight of approximately 0.44g, approximately 0.04g of starch needs to be added per tablet, meaning the starch amount is approximately 10% of the dry extract weight. Weigh the premixed coating material and starch according to this ratio, place them in the feed trough of a wet granulator, and dry mix for 5 minutes to ensure thorough and uniform mixing.

[0035] Subsequently, while continuously stirring, 10% starch slurry is slowly added to the mixed powder as a binder. The 10% starch slurry is prepared as follows: Take 10g of starch, add an appropriate amount of cold water and stir to disperse evenly. Then pour in boiling purified water and stir continuously until it gelatinizes into a semi-transparent state. Add water to bring the total weight to 100g, and let it cool for later use. The amount of starch slurry added is adjusted according to the dryness or wetness of the powder, usually 25%-35% of the total weight of the mixed powder, until the soft material can be formed into a ball when squeezed but crumbles easily when lightly pressed. The resulting soft material is transferred to a vibrating pellet mill and forced through a 14-mesh nylon sieve to form wet pellets. During sieving, the material must be added evenly to keep the sieve clear.

[0036] The wet granules are dried immediately after preparation. The wet granules are spread evenly on a stainless steel drying tray, with a layer thickness not exceeding 1.5 cm, and placed in a hot air circulating oven at 75℃-80℃ for drying. During drying, the granules are gently turned every 30 minutes to ensure even heating. Moisture changes are monitored using a rapid moisture analyzer, and the moisture content of the granules is controlled between 3% and 5% at the drying endpoint. Within this range, the granules possess both good compressibility and appropriate toughness; if too dry, the granules are brittle and prone to cracking during compression; if too wet, there is a high risk of sticking and impaction, and poor storage stability.

[0037] After drying, the granules are allowed to cool to room temperature before granulation. The dry granules are then passed through a 14-mesh sieve for granulation, and a vibrating sieve is used to remove fine powder and unbroken hard lumps. The portion that passes through the 14-mesh sieve is collected as granules for tableting. Using a 14-mesh sieve for granulation and granulation yields granules with a relatively concentrated particle size distribution, mainly between 14 and 80 mesh, resulting in good flowability and being highly beneficial for controlling tablet weight variation during compression.

[0038] After granulation, a lubricant is added for final mixing. Magnesium stearate, weighed at 0.5% of the granulated particle weight, is added to a multi-directional motion mixer and mixed at 10 rpm for 5 minutes to obtain the final mixed particles. The added magnesium stearate acts as a lubricant, adhering to the particle surface to improve flowability and release during tableting. Its function differs from the magnesium stearate used as a hydrophobic coating in step S2; both have different dosages and sites of action. The final mixing time should not be too long to avoid excessive coating and delayed tablet disintegration.

[0039] After the total granules passed quality inspection, tableting began. A rotary tablet press was used, equipped with a shallow concave circular die with a diameter of 11 mm. The filling depth and pressure were adjusted to achieve an average tablet weight of 0.44 g and a hardness controlled between 5 kg and 7 kg. During the tableting process, a certain number of tablets were sampled every 15 minutes to check for weight variation and appearance, ensuring that the weight variation was within ±5%. The granules prepared using this method have significantly reduced hygroscopicity because the dry extract powder is coated with hydrophobic excipients. No sticking occurred during the entire tableting process, and the tablet surface was smooth.

[0040] The compressed tablets can be coated as needed. Taking film-coating premix as an example, an 8% coating solution is prepared using 70% ethanol and coated in a high-efficiency coating machine. The inlet air temperature is set to 70℃, the tablet bed temperature is maintained at around 40℃, and the coating solution spray rate is controlled at 8ml-12ml per kilogram of tablets per minute until the coating weight gain reaches 2%-3% of the tablet core weight. The coating layer can further isolate external moisture and effectively mask the bitterness of the extract. The coated tablets have a uniform color and a smooth appearance.

[0041] To more comprehensively demonstrate the technical effects of this invention, three implementation scenarios and one comparative example were set up for systematic quality comparison and evaluation. The comparative example was prepared according to the process of the current pharmaceutical standard WS3-B-2777-97-2, that is, the dried extract of wild papaya was directly mixed with starch and granulated after being pulverized, without undergoing the hydrophobic excipient premixing and coating in step S2. Only 0.5% magnesium stearate was added as a lubricant during the total mixing. The remaining granulation and tableting conditions were the same as those in the implementation scenarios. Implementation scenarios one, two, and three correspond to the processes of 5% magnesium stearate coating, 3% magnesium stearate and 2% micronized silica gel combination coating, and 8% talc coating, respectively. The operating parameters of steps S1 and S3 are completely identical in all three, with differences only in the type, amount, and premixing parameters of the excipients in step S2.

[0042] Evaluation indicators included the moisture absorption rate of the premixed and coated dry extract powder, the soft material state during granulation, tablet sticking during compression, the initial disintegration time of the unmixed tablets, and the disintegration time after 3 months of accelerated testing. The moisture absorption rate was tested under conditions of 75% relative humidity for 24 hours. The accelerated testing conditions were a temperature of 40℃±2℃ and a relative humidity of 75%±5%, with aluminum-plastic blister packaging. The disintegration time was determined according to pharmacopoeia methods. Specific results are shown in Table 1.

[0043] Table 1. Comparison of quality data for different implementation scenarios and comparative examples: As shown in Table 1, the comparative sample without premixed coating exhibited a 24-hour moisture absorption rate of 15.0% for its dry extract powder. During granulation, the soft material became sticky and easily adhered to the equipment, resulting in significant tableting sticking issues. The initial disintegration time was 26 minutes; after 3 months of accelerated testing, the disintegration time exceeded 45 minutes, failing to meet the pharmacopoeia's requirements for tablet disintegration time. This indicates that moisture absorption caused the collapse of the internal pore structure of the tablet, severely deteriorating its disintegration performance.

[0044] In Scenario 1, after pre-coating with 5% magnesium stearate, the moisture absorption rate of the dry extract powder decreased to 7.5%, the granulation process was smooth, there was no sticking or impaction during tableting, and the initial disintegration time was shortened to 14 minutes. After 3 months of accelerated processing, the disintegration time was 21 minutes, still within a reasonable range. In Scenario 2, a composite coating of magnesium stearate and micronized silica gel was used, with a moisture absorption rate of 7.9%. Granulation and tableting performance were also excellent, with an initial disintegration time of 13 minutes, which was reduced to 19 minutes after 3 months of accelerated processing. In Scenario 3, 8% talc was used alone for coating, with a moisture absorption rate of 9.6%. The soft material was slightly sticky, and occasional sticking or impaction occurred during tableting, but it was still within an acceptable range. The initial disintegration time was 18 minutes, which was reduced to 26 minutes after accelerated processing, representing a fundamental improvement compared to the existing process.

[0045] In summary, pre-mixing and coating the dried wild papaya extract powder with hydrophobic excipients in step S2 can reduce the hygroscopicity of the powder from the source, thereby making the granulation and tableting operations in step S3 smoother. The initial disintegration time and the disintegration time after accelerated storage of the final product are reliably guaranteed. Specifically, using 5% magnesium stearate as the coating excipient, pre-mixing at 20 rpm for 20 minutes, forms the most balanced and effective hydrophobic barrier layer in reducing hygroscopicity, without adversely affecting disintegration. Magnesium stearate is a conventional pharmaceutical excipient and is safe and reliable within its dosage range.

[0046] Therefore, the neuralgia drug and its preparation method provided by this invention, through the synergistic cooperation of steps S1-S3, especially the premixing and encapsulation treatment in step S2, construct a hydrophobic barrier on the surface of the dry extract powder particles, effectively overcoming the process and quality problems caused by the excessive hygroscopicity of wild papaya dry extract. The entire method is simple to operate, requires no special equipment, and the obtained neuralgia drug has low hygroscopicity, good formability, and stable storage quality, possessing good industrial implementation value.

[0047] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing a neuropathic pain drug, characterized in that, The method includes the following steps: S1, crush the dried wild papaya extract through an 80-mesh sieve to obtain dried wild papaya extract powder; S2, add wild papaya dried extract powder and 3%-8% of hydrophobic excipients by weight of wild papaya dried extract powder into a mixer, premix for 15-30 minutes at room temperature, so that the hydrophobic excipients coat the surface of wild papaya dried extract powder particles to obtain premixed coated material. S3, the premixed coating material is mixed with starch, and 10% starch slurry is added to make a soft material. The material is then granulated, dried, sized, mixed, compressed, and coated in sequence to obtain a neuropathic drug.

2. The method for preparing a neuropathic pain drug according to claim 1, characterized in that, In step S2, the hydrophobic excipient is one or more of magnesium stearate, micronized silica gel, and talc.

3. The method for preparing a neuropathic pain drug according to claim 2, characterized in that, In S2, the hydrophobic excipient is magnesium stearate, and the amount of magnesium stearate used is 5% of the weight of the dried wild papaya extract powder.

4. The method for preparing a neuropathic pain drug according to claim 1, characterized in that, In step S2, the speed of the mixer is 10-30 r / min.

5. The method for preparing a neuropathic pain drug according to claim 4, characterized in that, The mixer rotates at 20 r / min, and the premixing time is 20 min.

6. The method for preparing a neuropathic pain drug according to claim 1, characterized in that, In S1, the dried wild papaya extract is prepared by the following method: Cut the wild papaya into sections, add water and decoct twice, 2 hours each time. Combine the decoctions, filter, concentrate the filtrate to a relative density of 1.30-1.35, heat at 80℃ to obtain a thick paste, dry the paste until the moisture content does not exceed 3% to obtain wild papaya dry extract.

7. The method for preparing a neuropathic pain drug according to claim 1, characterized in that, In step S3, the soft material is granulated by passing it through a 14-mesh sieve; The dried granules are sieved through a 14-mesh sieve for granulation.

8. The method for preparing a neuropathic pain drug according to claim 1, characterized in that, In step S3, the wet particles are dried at 75-80℃ until the particle moisture content is 3%-5%.

9. A method for preparing a neuropathic pain drug according to claim 1, characterized in that, In step S3, magnesium stearate is added for total mixing, and the amount of magnesium stearate added is 0.5% of the weight of the granulated particles.

10. A neuropathic pain medication, applicable to the preparation method of the neuropathic pain medication according to any one of claims 1-9, characterized in that, The neuropathic pain medication is prepared by the method described above.

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