Tablet coating machine by Aatir Ejaz

1. TOPIC :- Tablet Coating
Machine
Submitted By:
Md Aatir Ejaz

2. Tablet Coating Machine
• Tablet coating machine is the mechanical device that apply an
essentially dry, thin layer of coating material of the surface of
tablet dosage forms in order to confer benefits over uncoated
variety. It is an equipment that coats the outer surface of tablet
with a thin layer of coating material.
• To mask the taste, odour, and colour of the drug.
• To provide physical and chemical protection of the drug.

4. • To prevent decomposition of drug sensitive to air (oxygen), light, or
humidity
• To minimize the unpleasant taste of certain drugs that may come during
partial dissolution of the drug in buccal fluids during absorption
• To provide visual appeal and consistency smooth surface texture and
uniform distribution of colour.
• To serve as anticounterfeiting medium by incorporating tracer compounds
in the coating material.
• To allow containment of highly potent compounds in the core of the
tablet and thus, avoid exposure to personnel handling of the tablets an
essentially dry, outer layer of coating material is applied to the surface of
a dosage form in order to confer specific benefits over uncoated variety

5. Working principles of tablet coating machines
The working principles of tablet coating machines are
relatively simple. Tablet coating machines work by
applying coating ingredients in the form of a solution
to a group of tablets in a bed that may move
horizontally or vertically. A concurrent flow of heated
air facilitates evaporation of the solvents

6. Types of tablet coating machines
• Several companies have developed their own coating machines to
accommodate their coating processes. The several types tablet coating
machines currently available in the market are based on these three
principle types.
1. standard coating pan
• Pellegrini pan
• Immersion sword system
• Immersion tube system

7. 2. Perforated coating pan
• Accela-cota
• Hi-coater systems
• Driacoater
• Glatt coater
3. Fluidized bed or air suspension
coater
• High-pressure airless systems
• Low-pressure air atomized systems

8. • 1. Standard coating pan
• Standard coating pan consists of a circular metal pan mounted
somewhat angularly on the stand. The pan is 8 to 60 inches (15
and 200 cm) in diameter and is rotated on its horizontal axis by
a motor. The rotational movement of the pan causes the batch
of tablets loaded into the pan to tumble and make multiple
passes through the spray application zone.
• Coating solution is applied to the rotating tablet bed by spraying
in atomized form which can produce a faster and more even
distribution of solution than simply introducing it as a liquid.
•
• Heat air is directed into the pan and onto the tablet bed surface
and is exhausted by means of the ducts positioned through the
front of the pan

10. • Conventional coating pan
•
• In order to achieve significant drying efficiency, a number of modifications
were made to the design of the hot air handling equipment of standard
coating pan. Typical examples of such modifications include the design of
conventional coating pans with
•
1, an immersion sword system – the drying air is introduced through a
perforated metal sword device that is immersed in the tablet bed.
2, a baffled pan and diffuser (Pellegrini pan system) – which allows the
distribution of drying air uniformly through the tablet bed or pellets.
3, an immersion tube system – the tube is immersed in the tablet bed
where it delivers heated air through the spray nozzle built in the tip of the
tube.

12. • 2. The perforated pan systems
• Perforated coating pan consists of a perforated or partially
perforated drum that is rotated on its horizontal axis in an enclosed
housing. The coating solution is applied to the surface of the
rotating bed of the tablets through spraying nozzles that are
positioned inside the drum.
•
• Perforated pans became popular when pharmaceutical
manufacturers switched from organic solvent-based coatings to
aqueous coatings. The switch was a natural response to the volatility
of organic solvents; the high cost of explosion-proof installations,
which became necessary in the 1980s to account for that volatility;
and the introduction of the Clean Air Act and its amendments in the
early 1990s.

13. Perforated coating pans come in various designs
depending on the vendor, but the intention is to
maximize the drying capability of the machine so
as to minimize core penetration at high spray
rates. They can be completely automated for both
sugar coating and film coating processes.
Examples of perforated coating pans include:
a. Accela-cota & Hi-coater systems

14. b. Driacoater
In the Driacoater, the drying air is introduced through
the hollow perforated ribs located on the inside
periphery of the drum. As the coating pan rotates the
rib dip into the tablet bed and drying air passes up
through and fluidizes the tablet bed exhausting
through the back of the pan.

15. •Glatt coater (Glatt perforated coating pans) design
uses fully perforated drums – a feature which combines
maximum spray rates and extremely short process
times. In a Glatt coater, the drying air can be directed
from the inside the drum through the tablet bed and
out an exhaust duct; alternatively with an optional split
chamber plenum, drying air can be directed in the
reverse manner up through the drum perforations for
partial fluidization of the tablet bed. Several airflow
configurations are possible

17. 3. Fluidized bed or air suspension systems
•
• Fluidized-bed coating equipment or air suspension coaters are
highly efficient coating systems in which the coating solution is
sprayed on to tablets (or granules) that have been suspended in a
columnar chamber by a positive (warmed) airflow. The airflow is
controlled so that more air enters the center of the column, causing
the tablet to rise in the center. The tablets in the center move
upwards in the airflow and fall outwards and downwards to the
chamber wall, at which stage the process is continuously repeated
from the bottom part of the column. Coating solutions are
continuously applied from the spray nozzles located at the bottom
of the chamber or sprayed onto the top of the cascading tablet bed
by nozzles located in the upper region of the chamber.

18. • Tablet cores that are friable and
prone to chipping and edge
abrasion may be difficult to coat
even under the optimum
conditions in the fluidized bed
systems, owing to the relatively
rough tablet to tablet impact and
tablet chamber contact.

19. • Schematic diagrams for three basic processes used for fluid-bed film
coating
•
• There are basically two types of spray-atomization systems used to apply a
finely divided spray coating solutions or suspensions onto the tablets.
•
1. High-pressure airless systems
2. Low-pressure air atomized systems

20. Advantages of tablet coating machines
• The advantages of tablet coating machines will be listed with respect to the three principal types
Standard coating pan
• Faster and more even distribution of coating solutions or suspensions can be achieved when
atomizing system is used.
• Spraying can reduce the drying time between solution applications in sugar coating and allows for
continuous application of solution in film coating.
• It is applicable for both sugar and film coating processes.
• A significant improvement in the drying efficiency of the standard coating can easily be achieved
by an immersion sword system, use of a baffled pan and diffuser (pellegrini pan system), and
immersion tube systems.

21. Perforated pan systems
• Perforated pans, by design, tend to be more efficient users of energy.
• The design of the coating machine increases the drying efficiency,
which results in shorter coating times.
• Several airflow configurations are possible in Glatt coater.
• It can be used for both sugar and film coating processes.

22. Fluidized or air suspension systems
• The ability of air suspension coaters to simultaneously to suspend and
coat tablets leads to high coating efficiency.
• It offers an alternative to pan coating and is particularly popular for
coating multiparticulate systems.
• The two spray-atomization systems (high-pressure airless systems and
low-pressure air atomized systems) result in finely divided spray
leading to uniform thin films

23. Thank you