Pharma Education Network

Granulation Technology - Significance and Recent Advances

Granulation Technology - Significance and Recent Advances

Granulation Technology - The process used for particle enlargement through agglomeration technique, a unit operation useful in transformation for tablets and capsules is known as granulation. It involves the conversion of the fine powders into the fine flowing dust free granules. Granulation technology is more important in pharmaceutical industry.

Significance of Granulation

The process of granulation is performed in order to obtain:
1. To increase uniformity of API in final product.
2. To increase density of blend so that it occupies less volume per unit weight for better storage and shipment.
3. To facilitate metering or volumetric dispensing.
4. To reduce dust during granulation process.
5. To reduce toxic exposure and process related hazards.
6. To improve the appearance of the product.

Ideal Characteristics of Granules

1. Spherical shape : for improved flow
2. Narrow particle size distribution : for content uniformity
3. Sufficient fines : for filling void spaces and for better compression and compaction
4. Adequate moisture and hardness : for preventing breakage and dust formation

Primary Methods of Granule Formation

1. Solid bridges
2. Sintering
3. Chemical reaction
4. Crystallization
5. Deposition of colloidal particles

Mechanisms of Granulation

1. Wetting and Nucleation
2. Coalescence and Growth
3. Consolidation
4. Attrition and breakage

Types of Granulation

There are mainly two types of granulation methods i.e. it may be done via :
1. Dry granulation
2. Wet granulation

Dry Granulation

It involves mechanical compression (using slugs) and compaction (using roller compaction) to facilitate the agglomeration by formation of wet mass by adhesion.

Wet Granulation

It involves multiple unit processes such as wet massing, drying and screening of the powder mixture with complex time consuming, expensive, multiple equipments.

Granulation Technologies

There are a huge number of various kinds of newly developed technologies which are suitable for the processing and production of granules of desirable shapes and sizes, although the granule size used in the pharmaceutical industries ranges between 0.2 to 4.0 mm.
The granulation technologies most likely to be used are:
1. Roller compaction
2. Spray drying
3. Supercritical fluid
4. Low / high shear mixing
5. Fluid bed granulation
6. Extrusion
7. Spheronization

Recent Progress in Dry Granulation

The newly invented technique used for dry granulation is the PNEUMATIC DRY GRANULATION.

Pneumatic Dry Granulation

An innovative dry granulation technique, utilizing roller compaction and proprietary air classification to produce granules. In this method, powder particles are subjected to mild compaction force and the compacted mass is then converted into fine granules and separated from intended size ranges, by fractionating chamber by entraining in gas stream pneumatic system.

Recent Progress in Wet Granulation Technology

The wet granulation advancements involve the process of mixing water in the dry powder excipients along with binders and subjecting them to a granulator in order to obtain a wet granulation mass, which is then dried into a dry granular mass and sized to obtain desirable dry granules.

Innovations in Wet Granulation Technology

There are many newly found techniques used in this process, namely,
1. Reverse wet granulation
2. Steam granulation
3. Moist activated dry granulation
4. Thermal adhesion granulation
5. Melt granulation
6. Freeze granulation
7. Foam granulation

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