A Granulator is a multi-purpose processor equally suitable for high speed dispersion of dry powders, aqueous or solvent granulations, effervescent products, wet and melt pelletization. At GEA Pharma Systems we supply the complete range of Granulation process equipment. If you require support to select the right process / equipment for you, than do contact us.

Dry Mixing
Whatever the subsequent production steps, the formulation of an active compound and other excipients needs to be mixed homogeneously. Low shear mixing relies on the planetary movement of the mixer arm to achieve homogeneity, while high shear mixing uses a high intensity mixing blade resulting in a homogeneous blend. Which technique is most suitable depends on the subsequent production step. GEA Pharma Systems Systems can assist in making the right choice.

Special features:
Checking of blend homogeniety by NIR-Technology

Low Shear Wet Granulation
During granulation, the active compound and the other excipients are combined with a binder solution to form granules with a fixed composition. Low shear planetary granulation is a gentle process to achieve this goal.

High Shear Wet Granulation

The high shear granulation process combines the components of the formulation using a high speed mixing blade and chopper. This process results in granules of a fixed composition,
which avoids segregation in later processing steps. During the granulation process, density and compressibility of the product is modified to achieve the optimal flow and tabletting properties.

Top Spray Granulation

The top spray fluid bed granulator agglomerates finer particles into larger, free flowing granulates in a one-pot process. Ingredients are mixed and pre-heated by an upward flow of heated air. Granulation occurs by spraying liquid into the fluidized powder. The granules are subsequently dried with heated air. The top spray granulator can also be used for top spray coating, layering from liquids, and instantizing.

Special features
- One pot process
- Selection of air distributors

Spray Dryer Granulation
The fluid bed spray dryer granulator transforms suspensions or solutions into dry, freeflowing, dustless granules. A suspension or solution of the substance to be dried is sprayed onto warm air, simultaneously drying and agglomerating the product. Batch or continuous discharge is available in the continuous mode, the product is discharged at a controlled rate to maintain an optimum bed height.

Special features
- Compact unit
- Easy scale-up
- Batch or continuous discharge

A rotating high velocity air stream is established in the central agglomeration tube. Particles are picked up at the base of the tube and accelerated by the air stream. The particles come into contact with liquid droplets produced from the spray nozzle at the base of the tube \ the relative velocity of air, liquid droplets and particles are high so wetting is efficient and drying begins almost immediately. Most of the feed material is in the outer “holding area”, where the gas velocity is very low. Attrition is greatly reduced. The gas humidity is also low in the holding area so the material is  dry not sticky. Individual particles may make repeated cycles (typically from 10 to 1,000) through the tube, allowing very large agglomerates to be built up.

Melt Granulating
In a melt granulation process, the binder solution of a standard wet granulation process is replaced with a meltable binder. This binder can be added in molten form, but the high shear process offers the benefit of allowing the binder to be added in its solid state. Melting is achieved by the energy added through the mixer friction and the heated jacket of the bowl.

Substrate Production for Extrusion

Planetary mixing is an excellent method of producing the wet substrate needed for an extrusion process, especially if this substrate needs to be a dough or paste. Special mixing tools are available to enhance the mixing of doughs or pastes.

Wet Pelletizing
This process uses a Niro Rotary Atomiser spray to achieve excellent dispersion of binder liquid through the mix, and a special high-speed rotation blade for maximum movement of the product, for more efficient pelletization. A PTFE container-lining minimises the need for ‘top and tailing’, even with the most cohesive of products. Studies have shown that the PTFE liner - unique to Aeromatic-Fielder - can increase production efficiency by as much as 40%.

Alternatively, an extruder may be used, similar to those used for the manufacture of pellets. In a typical set-up all ingredients are pre-blended in a container after dispensing. Depending on the extruder design the liquid can be added in the extruder or mixed separately to the correct consistency. The material produced by the extruder is now not rounded in a spheronizer (as it would be for pellet manufacture) but transferred directly into a continuous fluid bed where it is dried to the desired moisture level.

Melt pelletization
This is an exceptionally fast method of producing pellets in a single step. The active material and binder are mixed in binder form then heated until the binder melts. A single batch is processed typically in just 15-20minutes, and needs no further drying.

| Dry Bonding
When low amounts of drugs should be administered via inhalation, the accuracy of current devices is not precise enough. Therefore the small drug particles are bonded to the course surface of lactose particles in a dry high shear process. This requires special technology - Aeromatic-Fielder’s expertise in this process provides; special impellers giving enhanced shear forces, loading systems allowing a precise layering of drug and excipient and often special containment devices such as BuckŪ split valves or Hicoflex™.

Effervescent Products
One granulate method using water
A very small amount of water is added to start the pre-effervescent reaction by which some of the carbondioxide is released during granulation, but by which water is also produced as a reaction product, this then acts as a granulation fluid producing more carbondioxide and also more water. This avalanche needs to be stopped at a certain point by starting the drying process and removing the water. This can be done using a high shear granulator with subsequent fluid dryer by discharging at the end of the granulation process the material into a pre heated fluid bed dryer.

Special note:
Technical article on Effervescent Production

Go to: Comparison of Granulation Methods