July 29, 2021: Pharmaceutical Interview Questions and Answers

#Granulation #GranulatorOperatingPrinciples #EquipmentClassificationsForGranulation

1. What is Granulation

Granulation is the process of creating granules. The powder morphology is modified through the use of either a liquid that causes particles to bind through capillary forces or dry compaction forces.

The process will result in one or more of the following powder properties:

Enhanced flow;
Increased compressibility;
Densification;
Alteration of physical appearance to more spherical, uniform, or larger particles;
And/or enhanced hydrophilic surface properties.

2. What are the Operating Principles of different Granulation?

Types of GranulationOperating Principles
Dry GranulationDry powder densification and/or agglomeration by direct physical compaction.
Wet High-Shear GranulationPowder densification and/or agglomeration by the incorporation of a granulation fluid into the powder with high-power-per-unit mass, through rotating high-shear forces.
Wet Low-Shear GranulationPowder densification and/or agglomeration by the incorporation of a granulation fluid into the powder with low-power-per-unit mass, through rotating low-shear forces.
Low-Shear Tumble GranulationPowder densification and/or agglomeration by the incorporation of a granulation fluid into the powder with low-power-per-unit mass, through rotation of the container vessel and/or intensifier bar.
Extrusion GranulationPlasticization of solids or wetted mass of solids and granulation fluid with linear shear through a sized orifice using a pressure gradient.
Rotary GranulationSpheronization, agglomeration, and/or densification of a wetted or non-wetted powder or extruded material.   This is accomplished by centrifugal or rotational forces from a central rotating disk, rotating walls, or both. The process may include the incorporation and/or drying of a granulation fluid.
Fluid Bed GranulationPowder densification and/or agglomeration with little or no shear by direct granulation fluid atomization and impingement on solids, while suspended by a controlled gas stream, with simultaneous drying.
Spray Dry GranulationA pumpable granulating liquid containing solids (in solution or suspension) is atomized in a drying chamber and rapidly dried by a controlled gas stream, producing a dry powder.
Hot-melt GranulationAn agglomeration process that utilizes a molten liquid as a binder(s) or granulation matrix in which the active pharmaceutical ingredient (API) is mixed and then cooled down followed by milling into powder. This is usually accomplished in a temperature controlled jacketed high shear granulating tank or using a heated nozzle that sprays the molten binders(s) onto the fluidizing bed of the API and other inactive ingredients.
Melt ExtrusionA process that involves melting and mixing API and an excipient (generally a polymer) using low or high shear kneading screws followed by cooling and then milling into granules. Thermal energy for melting is usually supplied by the electric/water heater placed on the barrel. Materials are either premixed or fed into an extruder separately. Melt extruder subclasses primarily are distinguished by the configuration of the screw. • Single screw extruder • Twin screw extruder

3. Equipment Classifications used for granulation.

Equipment typeSub classification descriptionSub classification
Dry GranulatorDry granulator subclasses primarily are distinguished by the densification force application mechanism.• Slugging • Roller Compaction
Wet High-Shear GranulatorWet high-shear granulator subclasses primarily are distinguished by the geometric positioning of the primary impellers; impellers can be top, bottom, or side driven.• Vertical (Top or Bottom Driven) • Horizontal (Side Driven)
Wet Low-Shear GranulatorWet low-shear granulator subclasses primarily are distinguished by the geometry and design of the shear inducing components; shear can be induced by rotating impeller, reciprocal kneading action, or convection screw action.• Planetary • Kneading • Screw
Low-Shear Tumble GranulatorAlthough low-shear tumble granulators may differ from one another in vessel geometry and type of dispersion or intensifier bar, no low-shear tumble granulator subclasses have been identified.• Slant cone • Double cone • V-blender
Extrusion GranulatorExtrusion granulator subclasses primarily are distinguished by the orientation of extrusion surfaces and driving pressure production mechanism.• Radial or Basket • Axial • Ram • Roller, Gear, or Pelletizer
Rotary GranulatorRotary granulator subclasses primarily are distinguished by their structural architecture. They have either open top architecture, such as a vertical centrifugal spheronizer, or closed top architecture, such as a closed top fluid bed dryer.• Open • Closed
Fluid Bed GranulatorAlthough fluid bed granulators may differ from one another in geometry, operating pressures, and other conditions, no fluid bed granulator subclasses have been identified.No sub class
Spray Dry GranulatorAlthough spray dry granulators may differ from one another in geometry, operating pressures, and other conditions, no spray dry granulator subclasses have been identified.No sub class
Hot-melt GranulatorAlthough, hot-melt granulator may differ from one another in primarily melting the 455 inactive ingredient (particularly the binder or other polymeric matrices), no 456 subclasses have been identified at this time.No sub class

4. What is integrated unit as per SUPAC?

When a single piece of equipment is capable of performing multiple discrete unit operations (i.e. mixing, granulating, drying), the unit was evaluated solely for its ability to granulate. If multifunctional units were incapable of discrete steps (fluid bed granulator/drier), the unit was evaluated as an integrated unit.

Source: fda.gov

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