Roller Compaction Dry Granulator

Common problems in the dry granulation process include:
High proportion of granules and fine powder, uniformity of compression, and material sticking to the roller.
1.The proportion of fine powder is relatively high: one solution is to use a grooved roller, and the uncompacted material usually leaks out from the side of the roller; the second method is to re-compress the fine powder. There is a risk, but repeated compaction of the material may cause it to lose its compressibility and affect the quality of the tablets; the third solution is to install vacuum degassing equipment.
2.Uniformity of compression: The pressure on the surface of the roller is not uniform. Even the pressure on materials in the same area will change with time. The fluctuation of pressure is mainly affected by the compression structure of the roller and the uniformity of the feed of the mixed material. Influence. The solution to the roller compression structure is to use a roller with narrow wheels on the edge to reduce the movement of the compressed material and make the material evenly distributed; the solution to the uniformity of the mixed material feed is to adjust the screw feeder speed and adjust the fluidity of the mixed material.
3.Material sticking to the roller: The problem of material sticking to the roller is relatively simple and can be solved by controlling the moisture content of the mixed material, adding lubricant, and repeated extrusion.

Generally, there are three main variables in the dry granulation rolling process: pressure, feed screw speed and roller speed; there are two main auxiliary materials in the mixed powder that have a greater impact on rolling: binders and lubricants, and easy Affected by the moisture content of the material.
1.The moisture content of the material affects: the deformation and tensile strength of the material, thereby affecting the compressibility of the tablet; therefore, during the dry granulation process, the moisture content must be strictly controlled even for the same material.
2.Influence of lubricants: The addition of lubricants will affect the compressibility of some materials. The amount and method of adding lubricants are the two most important aspects that affect the compressibility of tablets. In addition, the crystal form of the same lubricant and The specific surface area also affects the compressibility of the mixture.
3.Influence of binder: Binder can compensate for the loss of particle hardness, reduce the amount of fine powder during dry granulation and ensure the tensile strength of tablets; the correct selection of binder is important for the dry granulation process, especially For brittle API materials, particle size distribution is a key material attribute of adhesives.
4.Influence of roller pressure: When the roller pressure is low, the difference in compressibility loss for the same material is very small, but when the roller pressure is high, the compressibility loss of the same material will be large. Particles prepared at lower pressures have more pores and are more likely to break during tableting, resulting in high compressibility.
5.Influence of physical properties: Many APIs and excipients have different physical forms, including polymorphs, solvates, and amorphous forms. Even for the same material, there are batch-to-batch differences, such as particle size distribution, morphology (crystal form, crystal habit, agglomeration), surface roughness, etc., which will also affect the compressibility of the material during the dry granulation process.