High shear granulation consists of mixing (in special cases, some materials should be pre-mixed) and granulation. The adhesive still sprays down.
The liquid wets the drug surface and creates adhesion in the powder. Then under the action of liquid bridge and external force, the powder aggregates and forms particles of certain shape and size. Some common problems and disadvantages of high shear granulation include:
1. The material is seriously blocked, that is, excessive granulation
1) When the rubber material is fed too fast or too much or the granulation time is too long, the phenomenon of over-granulation will occur.
Therefore, granulation conditions should be controlled to avoid over-granulation.
2) Some solutions to avoid excessive granulation are: control the granulation time, check the current and check the torque. But these methods are not suitable for all materials. Therefore, the formulation should be tolerance tested for use in actual production.
2. Loose particles and excessive fines
1) High levels of ethanol in the binder will loosen the particles.
2) Small amount of binder or short granulation time will also affect granulation. Some materials do not granulate, so more fine powder is left behind.
3) Use of unsuitable binders, resulting in powders failing to form solid bridges. Stronger adhesives are recommended.
3. Some big wet granules and some powder
1) The stirring speed and rotation speed of the granulation impeller are too low to quickly distribute the binder.
2) Some materials are soluble in adhesives. Maybe change the adhesive.
3) Some materials become viscous when exposed to water. In this case, ethanol or an ethanol solution can be used as a binder.
Contact Person: Ms. Wei