What should we do if the tablet hardness does not meet the requirements

If the hardness of the tablet does not meet the requirements, the following aspects can be addressed:

1、 In terms of materials

1. Adjust the particle size of materials

Principle: The particle size of the material will affect the hardness of the tablet. Generally speaking, powders with smaller particle sizes have a larger contact area and tighter bonding between particles during the compression process, which is beneficial for improving tablet hardness. However, larger particles may have larger gaps between them during compression, resulting in looser tablets and lower hardness after compression.

Measure: The material can be crushed or screened to make the particle size distribution more reasonable. For example, crushing some large particle materials again to make their particle size meet the requirements for tablet pressing. If the material is a mixture of multiple components, it is also possible to consider adjusting the proportion of components with different particle sizes.

2. Improve the fluidity of materials

Principle: Good fluidity can ensure that the material is evenly filled into the mold. If the material has poor flowability and uneven filling, it can lead to inconsistent tablet density, which in turn affects hardness.

Measure: An appropriate amount of flow aid can be added, such as micro silica gel, talcum powder, etc. These flow aids can reduce the friction between material particles and improve the flowability of materials. The general dosage of micro powder silica gel is 0.1% -0.3%, and the dosage of talc powder is about 1% -3%. The specific dosage needs to be adjusted according to the material properties and actual situation.

3. Optimize the compressibility of materials

Principle: The compressibility of a material refers to its ability to form a tight bond under pressure. Some materials have poor compressibility and are difficult to form during the tablet pressing process, resulting in insufficient tablet hardness.

Measure: Adhesive can be added to enhance the compressibility of the material. Common adhesives include starch slurry, hydroxypropyl methylcellulose (HPMC), polyvinylpyrrolidone (PVP), etc. For example, using 5% -10% starch slurry as a binder, mixing it evenly with the material before pressing it, can better bond the material together during the pressing process and improve the hardness of the tablet.

2、 Tablet press aspect

1. Adjust the pressure

Principle: Increasing the pressure of the tablet press is the most direct way to improve the hardness of tablets. Within a certain range, the greater the pressure, the stronger the compression force on the tablet, the tighter the bonding between particles, and the higher the hardness.

Measure: Increase the main pressure appropriately according to the type and performance of the tablet press. But be careful not to excessively increase the pressure, otherwise it may cause problems such as tablet cracking and slow disintegration. At the same time, it is also necessary to pay attention to the adjustment of pre pressure. Appropriate pre pressure can discharge the air in the material, so that the material can be better formed during the main pressure.

2. Check the punch and mold

Principle: The wear and deformation of the punch and mold can affect the quality of tablet molding. For example, uneven surface of the punch can lead to uneven force and inconsistent hardness of the tablet during the compression process; Insufficient dimensional accuracy of the mold can also have adverse effects on the shape and hardness of the tablets.

Measure: Regularly check the wear of the punch and mold, and replace severely worn components in a timely manner. Ensure the correct installation of the punch and mold, and maintain good cleanliness to avoid material residue affecting the formation of tablets.

3. Control the compression speed

Principle: If the compression speed is too fast, the material may not have enough time to be fully compressed and formed in the mold, which can lead to a decrease in tablet hardness.

Measure: Reduce the compression speed appropriately to allow sufficient time for the material to form a tight structure under pressure. However, reducing the tablet pressing speed may affect production efficiency, and a balance needs to be struck between hardness and production efficiency. For example, for a high-speed tablet press, the tablet pressing speed can be reduced from the original high speed (such as several thousand tablets per minute) to a suitable speed, and the specific value needs to be determined based on the actual tablet pressing situation and equipment performance.