Granulation is the process of expanding powdered particles to form agglomerates. This step determines key characteristics such as particle shape and size distribution (PSD), flow properties, and crystal stability in the final product granulation machine.
Granulation is an essential process for pharmaceutical manufacturers who aim to create high-quality granules. Wet granulation is one of the most prevalent processes within this industry, yet proper equipment selection can significantly enhance performance.
Particle size reduction
Particle size reduction, also known as commination, is the process of breaking down a solid material into smaller particles. It’s commonly employed for processing solids, improving their performance properties or fulfilling specific manufacturing demands.
The efficiency of particle size reduction depends on several factors, including the tablet granulation machine technology and equipment employed, as well as the physical-chemical characteristics of the drug, such as hardness, porosity and morphology. If a technique produces amorphous drugs or highly brittle, porous and friable structures then it may not be effective at all.
Combinatorial processes were developed to address the drawbacks of standard commination techniques such as high pressure homogenization (HPH) and wet bead milling (WBM). These technologies offer faster top-down process steps, improved physical stability, and smaller final mean particle sizes than standard commination processes. They are particularly beneficial when formulating poorly soluble drugs that need improvement for increased bioavailability.
Agglomeration
Agglomeration, also referred to as agglomeration of particles, is the process of combining multiple, individually sized, often tacky solids into larger granules. It’s widely used in industrial powder handling processes due to its speedy transfer into water for de-aeration and solid dissolution.
Agglomeration has the primary goal of creating an even size distribution and minimizing segregation and compaction. It also permits control over particle de-aeration, dissolution rates and attrition resistance.
Can be caused by spraying a solvent or slurry onto particles, as well as controlled sintering, partial melting or wetting of binder components within the feed.
Agglomeration by compaction typically employs either a double roll press (roll compactor) or tablet presses to produce continuous sheets of material that are then broken up into uniform-sized granules in a granulation machine. This method combines the benefits of both agitation and compression methods for agglomeration.
Mixing
Granulation is the process of mixing ingredients in powder form to create a slurry-like mass that is then agglomerated into specific size range granules. This can be done with dry or wet ingredients.
Wet mixing is the process of adding a binder solution to powder blends to facilitate wetting and agglomeration. This liquid helps the particles adhere to each other, creating a wet mass.
This wet mass is then dried and screened to form granules of the desired size range. This can be accomplished using various technologies, such as roller compaction or wet granulation.
Double planetary mixers are an ideal option for producing granulations. These low-maintenance machines lack shaft seals, bearings, packing glands or stuffing boxes submerged in product and come with a vessel lift design which enables easy cleaning between batches.
Extrusion
Extrusion is a mechanical process that modifies the physical characteristics of powder or blend through flow characteristics, density and particle size.
Advanced ceramics utilize extrusion as their manufacturing process. This involves pushing powder through a die at high pressure until it emerges from the other side in its desired shape.
Granulation is an extrusion process that alters the physical characteristics of a powder or mix. Flow characteristics, density and particle size are three primary parameters affected by this procedure.
Conclusion
Typically, this process is dry with no solvents or binders required. However, in certain instances a binder may be added liquid form to raw material powders which could result in agglomeration. When selecting whether this type of binding and downstream drying process is suitable for your application, you must take into account both factors.
