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Flashcards in fluid bed Deck (12)
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1

mechanism of granualtion in fluid bed

1) droplet formation
2) evaporation
3) sticky droplets contact powder particles
4) open lattice 'snowflake' type granule
- good binder distribution
- good compressibility

2

choice of binder, viscosity and concentration play an important effect on granule formation and growth

choice of binder, viscosity and concentration play an important effect on granule formation and growth

3

characteristic of FB granule produced

1) open structure
2) bulk density similar to raw materials
3) good distribution of binder on surface
4) uniform and narrow particle size distribution
5) good texture

4

FB granulation is effective at production good quality granules, free-flowing and compressible

FB granulation is effective at production good quality granules, free-flowing and compressible

5

why drying?

1) to form a free flowing powder
2) to remove moisture (or organic solvent)
3) to condition/improve characteristic of product for the next process step

6

FSD fluid spray drying is ?

one step operation for the production of granues from liquid

produce granules suitable for direct compression

mix all ingredients in the liquid phase as a solution/suspension to spray dry and produce granules

7

benefits of microwave

1) penetrates into the product: drying at the core of the granules

2) does not depend on heat conduction
3) instant energy source
4) heat liquid (water and solvent) rarely the product
5) no effect on majority of granulation compounds

8

cons of microwave vacuum drying

1) limits for temperature sensitive products which require a very low residual moisture content
2) technique is still relatively unknown, which may lead to acceptance problems by the customer (NOT WITH REGULATORY BODIES)

3) more complicated and expensive

9

pros for microwave vacuum drying

1) energy supply independent from vessel wall, wall temperature can be controlled in order to avoid caking

2) no risk of wet lumps
3) significantly reduced drying time
4) scale up of drying time is linear (depending on microwave power installed)

10

drying too fast can influence granule quality

1) explosion of granule due to evaporation of liquid
2)if a gelling agent is used (eg HPMC) no time to hydrate so no time to bind (no bridge form)

11

spray drying produces

porous, spherical granules.

12

fluid bed granules

highly compressible and spherical