Granulation is the process of binding powder particles together to form larger multi-particle granules. It is done to improve powder flow properties, enhance content uniformity, and eliminate segregation issues. The main granulation techniques are wet granulation, dry granulation, and direct compression. Wet granulation involves mixing powders with a liquid binder to form granules, then drying the granules. Dry granulation compresses powders directly into tablets. Direct compression tablets are made by compressing blended powders without granulation. Granulation improves flow, content uniformity, and compression properties.

2. )

3. What is Granulation ?
“Granulation is the process of collecting particles together by
creating bonds between them. Bonds are formed by
compression or by using a binding agent.”
OR
“Granulation refers to the act or process in which primary
powder particles are made to adhere to form larger, multi-particle
entities called granules.”

4. NEED OF GRANULATION
 To avoid powder segregation.
 To enhance flow of powders.
 To produce uniform mixture.
 To produce dust free formulations.
 To eliminate poor content uniformity.
 To improve compaction characteristics.

5. TECHNIQUES FOR
GRANULATION PROCESS
Following are frequently used techniques employed in
industries for tablet manufacturing.
Wet Granulation
 Dry Granulation
 Direct Compression

6. FUNDAMENTAL PROCESSING STEPS OF
GRANULATION PROCESS

7. DRY GRANULATION:
“Pharmaceutical powders that were mixed homogeneously
together are compressed to obtain large tablets.”
REASONS FOR SELECTION OF DRY METHOD:
• Drug dose is to high.
• Heat sensitive.
• Moisture sensitive.
• Do not compress well after wet granulation.

8. Process can be carried out in two ways:
Large tablet produced
in heavy duty tablet
press.
Powders is squeezed
between two rollers to
produced sheet of
material.

9. WET GRANULATION:
“Wet granulation form the granules by binding the powder
together with an adhesive, instead of by compaction.”
STAGES OF WET GRANULATION:

10. We have three kinds of water in the granulate mass:
1. Water of Crystallization,
It is very difficult to be eliminated without causing the
decomposition of the product or variation of its crystalline
form.
2. Adsorped water,
The amount of water, which was absorbed by a drug
present in a moist air, this amount depends on the nature of
the drug & the relative humidity of the air.
3. Imbibition of water,
The amount of water, which impregnates the granules, this
water is easy to be eliminated by simple evaporation.

11. ADVANTAGES OF GRANULATION PROCESS
DIRECT
COMPRESSION
DRY
GRANULATION
WET
GRANULATION
 Fewer processing
steps – blending and
compression -reduced
processing time
 Processing without
moisture and heat –
fewer stability problems
 Rapid and most direct
method of tablet
compression
 Improved flow by
increasing particle size
 Improved cohesion
during compression
 Granulation without
addition of liquid
 Improved flow by
increasing particle size
 Uniform distribution
of API, colour etc. –
improved content
uniformity
 Good for bulky
powders, less dust and
environmental
contamination
 Lower compression
pressure, less wear and
tear on tooling

12. DISADVANTAGESOF GRANULATION PROCESS
DIRECT
COMPRESSION
DRY
GRANULATION
WET
GRANULATION
 Possibility of lot to lot
variations due to differences
in flowability and moisture of
excipients
 Higher risk of content
uniformity failure in low dose
products.
 Lack of moisture can
create static charges that can
result in un-blending
 Possible particle
segregation
 Greater
possibility of cross
contamination
 Large number of
processing steps
 More equipment
Wetting and drying
stages are time
consuming

13.  Steam Granulation
 Melt Granulation / Thermoplastic Granulation
 Moisture Activated Dry Granulation (MADG)
 Moist Granulation Technique (MGT)
Thermal Adhesion Granulation Process (TAGP)
 Foam Granulation

14. STEAM GRANULATION
It is a modification of wet granulation; steam is used as a
binder instead of water; granules are more spherical and
exhibit higher rate of dissolution.
MELT GRANULATION
Granulation is achieved by the addition of meltable binder i.e.
binder is in solid state at room temperature but melts in the
temperature range of 50 – 80˚C e.g. PEG (water soluble),
stearic acid, cetyl or stearyl alcohol (water insoluble).
However drying phase unnecessary since dried granules are
obtained by cooling them to room temperature.

15. MOISTURE ACTIVATED DRY GRANULATION (MADG):
Involves distribution of moisture to induce agglomeration –
drying time is reduced.
MOIST GRANULATION TECHNIQUE (MGT)
A small amount of granulating fluid is added to activate dry
binder and to facilitate agglomeration. Then a moisture
absorbing material like Microcrystalline Cellulose (MCC) is
added to absorb any excess moisture making drying step
unnecessary. Mainly employed for controlled release
formulations.

16. THERMAL ADHESION GRANULATION PROCESS
(TAGP)
Granules are prepared by moisturizing excipient mixtures with
very little solvent in a closed system (tumble mixing) with low
heating – mainly employed for preparing direct compression
formulations
FOAM GRANULATION
Binders are added as aqueous foam.