A method for preparing finasteride tablets

Abstract

This invention discloses a method for preparing finasteride tablets, relating to the field of pharmaceutical preparation technology. The method includes: preparing a surfactant into an aqueous solution, adding a first-prescription amount of binder to form a binder suspension; premixing finasteride, a filler, a first-prescription amount of disintegrant, and a second-prescription amount of binder to obtain a premixed material; adding the binder suspension to the premixed material for wet granulation to obtain wet granules; drying and sizing the wet granules, then mixing them with a second-prescription amount of disintegrant and lubricant, and compressing the mixture into tablets. This invention, while ensuring rapid tablet release, achieves the production of tablets with suitable hardness and stable properties at a relatively low compression pressure. Furthermore, this invention utilizes non-organic solvents for granulation, significantly improving the stability, safety, and industrial production efficiency of the final product without the addition of non-standard excipients.

Description

Technical Field

[0001] This invention relates to the field of pharmaceutical preparation technology, and in particular to a method for preparing finasteride tablets. Background Technology

[0002] Finasteride is a synthetic steroidal compound used clinically as a specific inhibitor of type II 5α-reductase, primarily for the treatment of androgenetic alopecia and benign prostatic hyperplasia in men. The formulation of the marketed original product, Propecia (PROSCAR®), has undergone rigorous validation. Its main excipients include lactose (monohydrate), microcrystalline cellulose, pregelatinized starch (as a binder), sodium carboxymethyl starch (as a disintegrant), magnesium stearate (as a lubricant), and sodium docusate (as a surfactant). In traditional manufacturing processes, the pregelatinized starch in the formulation is typically prepared into a starch slurry for use as a binder. While starch slurry provides a noticeable granular texture, the wet granulation process parameters are extremely difficult to control in actual production, easily leading to unstable granule quality and hindering large-scale commercial production.

[0003] To optimize production, researchers have proposed several improvement schemes. For example, patent CN110623935A discloses a preparation process containing hydroxypropyl methylcellulose (HPMC), which improves granule properties by adding 2% HPMC. This approach alters the standard formulation of the original drug, adding additional binders, which may introduce new quality risks or affect bioequivalence. Patent CN109893512A attempts to formulate an aqueous surfactant solution as a binder, adding this solution after dry mixing of raw materials, fillers, and disintegrants for granulation. Although such schemes improve dissolution uniformity to some extent, balancing granule flowability and compressibility, and ensuring high consistency of product dissolution profiles between and within batches, remains a challenge for industrial production.

[0004] Therefore, the key issue that urgently needs to be addressed to achieve high-standard industrial production of finasteride tablets is how to develop a simple, controllable, and significantly improved particle physical properties and dissolution uniformity preparation method while maintaining complete consistency with the original formulation and without adding non-standard excipients. Summary of the Invention

[0005] The technical problem to be solved by this invention is how to develop a method for preparing finasteride tablets that is simple in process, has controllable parameters, and can significantly improve the physical properties of particles and the uniformity of dissolution, while maintaining the same formulation as the original formulation and without adding any non-standard excipients.

[0006] To address the above problems, the present invention proposes the following technical solution: In a first aspect, the present invention provides a method for preparing finasteride tablets, comprising the following steps: (i) After preparing the surfactant into an aqueous solution, add the first prescription amount of adhesive and stir to form an adhesive suspension slurry; (ii) The finasteride raw material, filler, disintegrant in the first prescription amount and binder in the second prescription amount are premixed to obtain a premixed material; (iii) The binder suspension slurry described in step (i) is added as a wetting agent to the premixed material described in step (ii) for wet granulation to obtain wet granules; (iv) After drying and granulating the wet granules, mix them with the second prescription amount of disintegrant and lubricant, and compress them into tablets to obtain the final product.

[0007] Further, the mass concentration of the surfactant aqueous solution in step (i) is 0.2% to 10%.

[0008] Further, the solid content of the adhesive suspension slurry in step (i) is 1% to 20%.

[0009] Further, in step (i), the first formulation amount of the binder is 0.5% to 8% of the total weight of the tablets; in step (ii), the second formulation amount of the binder added in dry powder form is 4.5% to 12% of the total weight of the tablets.

[0010] Furthermore, the mass ratio of the first formulation amount to the second formulation amount of the disintegrant is 0:1 to 1:0, and neither the first formulation amount nor the second formulation amount is 0.

[0011] Furthermore, the drying process described in step (iv) controls the particle moisture content to be ≤3.0%.

[0012] Furthermore, the surfactant is sodium docusate, and the adhesive is pregelatinized starch.

[0013] Furthermore, the disintegrant is sodium carboxymethyl starch, the lubricant is magnesium stearate, and the filler is lactose and microcrystalline cellulose.

[0014] Furthermore, the finasteride tablets are composed of the following components in weight percentage: Finasteride 0.05%~1%, lactose 50%~80%, microcrystalline cellulose 10%~20%, pregelatinized starch 5%~20%, sodium carboxymethyl starch 2%~7%, sodium docusate 0.05%~1.5%, magnesium stearate 0.5%~3%.

[0015] The present invention also provides a finasteride tablet, which is prepared by the preparation method described above.

[0016] Compared with the prior art, the technical effects achieved by the present invention include: The method for preparing finasteride tablets provided by this invention involves first preparing an aqueous solution of surfactant and then adding a portion of binder to form a suspension slurry. This results in a more uniform dispersion of the binder in the slurry, while the surfactant enhances the wettability of the liquid on the surfaces of raw material and excipient particles. Consequently, more thorough and stable coating and wetting of the materials are achieved during granulation. Compared to simply adding all the binder in dry powder form, this method reduces particle size distribution differences caused by uneven particle bonding. The angle of repose and Cartesian coefficient of the resulting particles are improved, and the flowability is significantly enhanced, which is beneficial for the stable operation of subsequent tableting processes and parameter control in commercial production.

[0017] This invention adds disintegrants internally during the premixing stage and externally during the total mixing stage, with a reasonable distribution of the internal and external addition ratios. This results in a multi-stage disintegration and dissolution process when the tablets come into contact with the dissolution medium, where the initial action of the internal disintegrants and the synergistic release of the external disintegrants combine. This avoids release rate fluctuations caused by a single concentrated action of the disintegrants, effectively reduces the relative standard deviation of dissolution rates between tablets within the same batch and between different batches, and improves the intra-batch and inter-batch uniformity of the product's dissolution profile.

[0018] This invention, by employing the specific feeding sequence and distribution process described above, optimizes the physical properties of the granules and improves their compressibility while ensuring rapid tablet release. This allows for the production of unprocessed tablets with suitable hardness and stable properties at relatively low compression pressure. Furthermore, by utilizing non-organic solvents for wet granulation and combining it with appropriate process steps, this invention significantly improves the stability, safety, and industrial production efficiency of the final product without the addition of non-standard excipients. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the preparation method of finasteride tablets provided in an embodiment of the present invention. Detailed Implementation

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Similar component reference numerals in the drawings represent similar components. Obviously, the embodiments described below 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.

[0021] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0022] It should also be understood that the terminology used in the specification of embodiments of the present invention is for the purpose of describing particular embodiments only and is not intended to limit the embodiments of the present invention. As used in the specification of embodiments of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a," "an," and "the" are intended to include the plural forms.

[0023] The formulation of the finasteride tablets of this invention is consistent with the publicly disclosed information of the original formulation Propecia (PROSCAR®), comprising, by mass percentage: 0.05%–1% finasteride, 50%–80% lactose (monohydrate), 10%–20% microcrystalline cellulose, 5%–20% pregelatinized starch, 2%–7% sodium carboxymethyl starch, 0.05%–1.5% sodium docusate, and 0.5%–3% magnesium stearate. Based on this, embodiments of this invention improve particle shapeability and release uniformity during wet granulation by optimizing the method of adding the binder and the internal and external distribution ratio of the disintegrant. The details are as follows: See Figure 1 This invention provides a method for preparing finasteride tablets, comprising the following steps: (i) After preparing the surfactant into an aqueous solution, add the first prescription amount of adhesive and stir to form an adhesive suspension slurry.

[0024] In practice, the prescribed amount of surfactant sodium docusate is first dissolved in purified water to prepare an aqueous solution with a mass concentration of 0.2% to 10%. Then, the first prescribed amount of binder is added to this solution and stirred continuously to form a binder suspension with a solid content of 1% to 20%. The amount of this binder accounts for 0.5% to 8% of the total tablet weight, for example, 0.5%, 1.0%, 3.0%, 5.0%, 6.0%, or 8.0%. During this process, the surfactant molecules are pre-dissolved in water, which significantly reduces the surface tension of the water. When in contact with pregelatinized starch, it can quickly wet the surface of the starch granules and promote appropriate dissolution and swelling of starch segments, forming a suspension system with a certain viscosity. This suspension combines the wetting and spreading ability of surfactants with the adhesive properties of pregelatinized starch, enabling effective coating of finasteride and excipient particles during subsequent granulation.

[0025] In specific implementations, the concentration of the surfactant aqueous solution can be 0.2%, 0.8%, 1.5%, 3.5%, 5.5%, 8.5%, or 10.0%. If the surfactant aqueous solution concentration is below 0.2%, the wetting effect is insufficient, and the material is difficult to be uniformly wetted; if the concentration is above 10%, the solution is prone to generating excessive foam, interfering with subsequent granulation operations. The solid content of the binder suspension slurry is exemplarily 1%, 2.5%, 5.5%, 8.5%, 10%, 14%, 16%, 18%, or 20.0%. When the solid content is below 1%, the slurry is too thin and cannot form an effective coating layer on the particle surface; when the solid content is above 20%, the slurry fluidity decreases, making it difficult to apply evenly and potentially leading to localized over-wetting and clumping of the material.

[0026] (ii) The finasteride raw material, filler, disintegrant in the first prescription amount and binder in the second prescription amount are premixed to obtain a premixed material; In practice, finasteride raw material, fillers (lactose and microcrystalline cellulose), a first-formulation amount of disintegrant (added portion of sodium carboxymethyl starch), and a second-formulation amount of binder powder (the remaining pregelatinized starch, added in dry powder form) are placed in a wet granulator for dry mixing to obtain a premixed material. The second-formulation amount of binder powder is 4.5% to 12% of the total tablet weight, for example, 4.5%, 6.0%, 8.0%, 9.0%, 10.0%, or 12.0%. The sum of the first and second-formulation amounts of binder is 5% to 20%.

[0027] In specific implementation, the mass ratio between the first prescription amount of disintegrant and the second prescription amount of disintegrant added in the subsequent total mixing stage is 0:1 to 1:0, for example, 2:8, 4:6, 5:5, 6:4, or 8:2, wherein neither the first nor the second prescription amount is 0. That is, the disintegrant in this invention is added in batches, avoiding the use of entirely internal or entirely external addition (i.e., a ratio of 0:1 or 1:0) to achieve multi-stage disintegration control. The ratio of internal to external addition is preferably controlled between 4:6 and 6:4, for example, 4:6, 5:5, or 6:4. If the proportion of the first prescription amount of disintegrant is too low (i.e., the internal addition ratio is less than 20%), there are fewer disintegration channels inside the tablet, and the initial release during dissolution may be slower; if the proportion of the first disintegrant is too high (i.e., the internal addition ratio is greater than 80%), the number of disintegration sites inside the particles increases and their distribution is not easily uniform, resulting in differences in the internal structure of the tablets, causing inconsistent disintegration initiation rates among different tablets, thus affecting the intra-batch and inter-batch uniformity of the dissolution profile.

[0028] (iii) The binder suspension slurry described in step (i) is added as a wetting agent to the premixed material described in step (ii) for wet granulation to obtain wet granules.

[0029] In practice, the binder suspension prepared in step (i) is used as a wetting agent, which is sprayed evenly through a nozzle or added to the premixed material in step (ii) in one go. Simultaneously, the agitator and cutter are activated, allowing the material to form wet granules of suitable size through wetting, kneading, and shearing. The addition rate of the suspension and the granulation time can be adjusted according to the batch size and equipment capacity. The goal is to agglomerate fine powder into granules through uniform wetting of the slurry. During this process, the surfactant sodium docusate continuously reduces the surface tension of water, helping water to quickly penetrate the internal pores of the raw materials and excipients. Pregelatinized starch forms an adhesive network inside and outside the granules, allowing finasteride to tightly bind with brittle materials such as lactose and microcrystalline cellulose. The particle size and distribution of the wet granules can be controlled by the stirring speed and cutting time: if the stirring speed is too low or the time is too short, the powder is not sufficiently wetted, resulting in too much fine powder; if the stirring speed is too high or the time is too long, the granules are over-compacted, leading to difficulties in subsequent drying and reduced compressibility during tableting. Suitable wet particles should appear as loose, moist, and uniform granular aggregates.

[0030] (iv) After drying and granulating the wet granules, mix them with the second prescription amount of disintegrant and lubricant, and compress them into tablets to obtain the final product.

[0031] In practice, the wet granules obtained in step (iii) are transferred to a fluidized bed dryer or oven for drying. The dried granules are then granulated through a 24-mesh sieve to break up agglomerates and achieve uniform particle size, resulting in regularly sized dry granules. After granulation, the dry granules are added to a mixer along with the second prescribed amount of disintegrant (additionally added sodium carboxymethyl starch) and the lubricant magnesium stearate for total mixing. The mixing time is adjusted to ensure uniform distribution of all components. The mixed granules are then compressed into tablets using a rotary tablet press. Finally, the tablets can be coated with a film according to conventional processes to improve appearance, mask taste, or enhance moisture resistance, thus obtaining the finasteride tablet product. The mixed granules obtained in this embodiment have good flowability and compressibility, and can be compressed into tablets of suitable hardness under relatively low tableting pressure.

[0032] It should be noted that the drying temperature is generally controlled between 60℃ and 80℃ until the particle moisture content drops below 3.0%, for example, to 3.0%, 2.5%, 2.0%, or 1.0%. Moisture content control has a direct impact on formulation stability: when the particle moisture content exceeds 3.0%, finasteride-related impurities tend to grow more rapidly during storage, reducing product safety; when the moisture content is controlled below 3.0%, the tendency for impurity formation is significantly reduced. Those skilled in the art can control the moisture content by controlling the drying temperature or time. Understandably, if the drying temperature is too low or the time is insufficient, the residual moisture content of the particles will be too high, easily leading to excessive impurities; if the drying temperature is too high or the time is too long, even if the moisture content is extremely low, the particles may become over-hardened, losing compressibility, and increasing energy consumption.

[0033] To better illustrate the technical solution of the present invention, the key parameters in the preparation method are examined through several specific embodiments below. The formulation composition of each embodiment is detailed in Table 1.

[0034] Specifically, in Example 1, the entire amount of pregelatinized starch was directly added to the granulation substrate in dry powder form for premixing, and only a surfactant was used to prepare the binder suspension. In Example 2, a portion of the pregelatinized starch was prepared into a suspension with an aqueous solution of sodium docusate, and the remaining pregelatinized starch was premixed in dry powder form, with the disintegrant being added internally and externally in equal proportions. In Example 3, all the disintegrant was added internally, based on Example 2. In Example 4, all the disintegrant was added externally, based on Example 2. In Example 5, sodium docusate was not used, and only a portion of the pregelatinized starch was used to prepare the suspension. In Example 6, hydroxypropyl methylcellulose was used instead of pregelatinized starch to prepare a suspension separately. In Example 7, the ratio of internal to external disintegrant was adjusted to 6:4, and the other conditions were the same as in Example 2. In Example 8, the ratio of internal to external disintegrant was adjusted to 4:6, and the other conditions were the same as in Example 2. Table 1. Formulation composition of Examples 1-8 The preparation processes of the above embodiments all follow the following general procedure: Finasteride, lactose, microcrystalline cellulose, pregelatinized starch, and sodium carboxymethyl starch are weighed in the prescribed amounts, mixed evenly in a wet granulator, and a binder suspension or wetting solution prepared according to the corresponding formula is added. The mixture is stirred and cut to obtain wet granules. After granulation through an 18-mesh sieve, the wet granules are dried in a fluidized bed at 60℃~80℃ until the moisture content meets the requirements, granulated through a 24-mesh sieve, and then the added sodium carboxymethyl starch and magnesium stearate are added for total mixing. The mixture is then compressed into tablets according to the theoretical tablet size, and film coating is performed if necessary. The powder properties test results of the granules prepared in each embodiment are shown in Table 2, the main compression pressure and tablet hardness data are shown in Table 3, and the dissolution curve and intra-batch homogeneity data of the finished product in purified water are shown in Table 4. The dissolution curve was determined according to the dissolution and release determination method (Chinese Pharmacopoeia 2025 Edition, General Chapter 0931, Method II). Using 900ml of water as the dissolution medium, and rotating at 50 revolutions per minute, samples were taken at 5 min, 10 min, 15 min, and 20 min.

[0035] Table 2. Powder Analytical Results of Total Mixtures in Examples 1-8 Table 3. Main pressure and tablet hardness of Examples 1-8 Table 4. Dissolution results of the finished products (within batch) in purified water from Examples 1-8 The results in Tables 2, 3, and 4 show that, compared to Example 1, Example 2 used a docusate sodium aqueous solution mixed with a portion of pregelatinized starch to form a suspension before granulation, while Example 1 added all the pregelatinized starch in dry powder form without using a surfactant slurry. The results indicate that the bulk density and tap density of the total mixed particles obtained in Example 2 were significantly improved, the Karl Fischer coefficient and angle of repose were significantly reduced, the proportion of particles in the target particle size range was greatly increased, and the proportion of fine powder was significantly reduced. Furthermore, the tableting pressure required in Example 2 was also lower. This demonstrates that the present invention, by using a surfactant aqueous solution to prepare a binder suspension slurry, can effectively improve the flowability and particle size distribution regularity of particles and reduce the main pressure required for tableting.

[0036] Compared to Example 5, Example 2 used a suspension of sodium docusate and pregelatinized starch, while Example 5 only used pregelatinized starch solution as a wetting agent and did not add sodium docusate to the slurry. The results showed that Example 2 had a higher particle density, significantly lower Karl Fischer coefficient and angle of repose, a significantly larger proportion of the target particle size range, and a lower proportion of fine powder. This indicates that the present invention, by further adding a binder to the surfactant solution to form a suspension, can significantly improve the aggregation and flowability of particles compared to using a surfactant solution alone, avoiding the problems of loose particles and excessive fine powder caused by insufficient adhesion.

[0037] Compared to Examples 3, 4, 2, and 7, Example 8 adjusts the ratio of internal to external disintegrant to approximately 4:6. Regarding particle flowability, Example 8 exhibits a lower Karl Fischer coefficient and angle of repose, indicating good flow performance. In the tableting process, Example 8 requires significantly lower main compression pressure than other disintegrant distribution schemes to achieve similar tablet hardness, demonstrating superior compressibility. Regarding dissolution behavior, Example 8 shows smaller batch-to-batch differences in dissolution at various sampling time points, with the relative standard deviation at each time point controlled at a low level, resulting in better consistency of the dissolution curve. This demonstrates that by optimizing the ratio of internal to external disintegrant to a suitable range, the present invention can further improve particle compressibility and significantly enhance the batch-to-batch uniformity of the product dissolution curve while ensuring good particle flowability.

[0038] Based on the combined results in Tables 2, 3, and 4, Example 8 exhibits the best overall performance in terms of particle flowability, compressibility, and dissolution uniformity. Example 8 has a Karl Fischer coefficient of only 16.4% and an angle of repose of 33°; its main compression pressure range is the lowest among all examples, requiring only 5.6–7.5 kN to obtain tablets with an average hardness of 56.1 N; its 5-minute dissolution RSD is 3.8%, its 10-minute RSD is 2.0%, and its 15-minute RSD is 0.2%. This demonstrates that by optimizing the preparation method of the binder suspension slurry and the synergistic application of the disintegrant in a 4:6 ratio, the present invention can produce particles with excellent flowability, high compressibility, and highly uniform dissolution behavior, providing a reliable quality control basis for industrial production.

[0039] To further examine the reproducibility of the optimized process, three batches of samples were prepared based on the formulation and preparation parameters of Example 8, designated as Examples 9, 10, and 11. The preparation process of the three batches of reproducible samples was exactly the same as that of Example 8, namely, using sodium docusate aqueous solution and a portion of pregelatinized starch to prepare a binder suspension, with the remaining pregelatinized starch premixed in dry powder form, and the ratio of internal to external disintegrant being 4:6. The samples were dried until the moisture content of the particles was ≤3.0%, and then granulated, mixed, compressed, and coated. The dissolution curves of the three batches of reproducible samples and the reference formulation in purified water are compared in Table 5.

[0040] Table 5. Dissolution results of the reference formulation (Propecia®) in purified water for Examples 8, 9-11, and Examples 9-11. As shown in Table 5, the dissolution curves of the three batches of samples prepared based on the process parameters of Example 8 (Examples 9, 10, and 11) in purified water exhibited good consistency with those of Example 8. The RSDs of each batch at each sampling time point were all below 5.0%, and the dissolution curves showed a high degree of overlap, indicating that the preparation method provided by this invention has high process reproducibility, with minimal differences in dissolution behavior between different batches, thus ensuring consistent batch-to-batch quality in commercial production.

[0041] To investigate the impact of particle moisture content on product stability during the drying process, samples were prepared using the wet particles obtained in Example 8 under different moisture conditions at the drying endpoint, and the changes in related substances during accelerated stability testing were examined. The results of related substance detection under each moisture condition are shown in Table 6.

[0042] Table 6. Accelerated stability results of the finished product (different moisture content) in Example 8 after 6 months. As shown in Table 6, the related substances test results after accelerated storage for 6 months under different particle moisture conditions in Example 8 indicate that moisture content has a significant impact on the stability of finasteride tablets. When the particle moisture content is 7.0%–5.0%, the total impurity content reaches 0.58% after 6 months of accelerated storage, with impurity B at 0.24% and impurity C at 0.16%. When the particle moisture content is 4.0%–3.0%, the total impurities decrease to 0.36%. When the particle moisture content is controlled below 3.0%, the total impurities after 6 months of accelerated storage are only 0.11% or less, with the total impurities being 0.08% when the moisture content is between 2.0% and 1.0% and 0.06% when the moisture content is below 1.0%. This demonstrates that by strictly controlling the moisture content of the dried particles to below 3.0%, the present invention can effectively inhibit the formation of related impurities in finasteride during storage, thereby improving the safety and stability of the product.

[0043] In summary, the finasteride tablet preparation method provided by this invention effectively improves the wetting and binding behavior of materials during wet granulation by combining the strategy of first preparing the surfactant into an aqueous solution, then adding a portion of the binder to form a suspension slurry, and finally adding the remaining binder dry powder internally. This results in significantly improved bulk density and tapped density of the prepared granules, a marked decrease in the Karl Fischer coefficient and angle of repose, a substantial increase in the proportion of particles within the target size range, and a decrease in the proportion of fine powder, exhibiting excellent flowability and a regular particle size distribution. Simultaneously, by distributing and optimizing the disintegrant through a combination of internal and external addition to a suitable ratio range, the main pressure required in the tableting process is significantly reduced, indicating an effective improvement in particle compressibility. Regarding dissolution behavior, the tablets prepared using the preferred process of this invention show a low relative standard deviation of dissolution at different sampling time points. The release rates among individual samples within each batch are highly consistent, and the dissolution curves of multiple batches prepared repeatedly with the same process parameters match well, with small batch-to-batch quality differences, indicating that this method has good process reproducibility. Furthermore, by controlling the moisture content of the dried particles to a low level, the growth of related substances in the accelerated stability test was effectively suppressed, and the impurity level was maintained within the specified limits, further ensuring the safety and shelf-life stability of the formulation. Overall, this invention, without altering the original formulation composition, achieves significant results in improving powder properties, increasing tableting efficiency, and ensuring product quality consistency by optimizing the binder preparation method and disintegrant distribution ratio. The process is simple and controllable, and has good prospects for industrial implementation.

[0044] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0045] The above description describes specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered 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 process for the preparation of finasteride tablets, characterized in that, Includes the following steps: (i) After preparing a sodium docusate solution with a mass concentration of 0.2% to 10%, add the first prescription amount of binder and stir to form a binder suspension with a solid content of 1% to 20%. (ii) The finasteride raw material, filler, disintegrant in the first prescription amount and binder in the second prescription amount are premixed to obtain a premixed material; (iii) The binder suspension slurry described in step (i) is added as a wetting agent to the premixed material described in step (ii) for wet granulation to obtain wet granules; (iv) After drying and granulating the wet granules, mix them with the second prescription amount of disintegrant and lubricant, and compress them into tablets to obtain the final product; The adhesive is pregelatinized starch, the disintegrant is sodium carboxymethyl starch, the lubricant is magnesium stearate, and the filler is lactose and microcrystalline cellulose; In step (i), the first formulation amount of the binder is 3.0% to 8% of the total weight of the tablets; in step (ii), the second formulation amount of the binder added in dry powder form is 4.5% to 12% of the total weight of the tablets; the mass ratio of the first formulation amount to the second formulation amount of the disintegrant is 2:8 to 8:

2. In step (iv), the drying process controls the particle moisture content to be ≤3.0%. The finasteride tablets are composed of the following components by weight percentage: Finasteride 0.05%~1%, lactose 50%~80%, microcrystalline cellulose 10%~20%, pregelatinized starch 5%~20%, sodium carboxymethyl starch 2%~7%, sodium docusate 0.05%~1.5%, magnesium stearate 0.5%~3%.

2. A finasteride tablet, characterized by, It is prepared by the preparation method described in claim 1.

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