It involves the introduction of tablet, advantage, disadvantages, method of preparation, defects or problem involves in manufacturing of tablets.

1. Palak Agrawal
M.Pharm

2.  Introduction
 Advantages
 Disadvantages
 Method of preparation
 Defects of tablet or problems in
manufacturing of tablet

3. “Tablet is a solid dosage form containing a medicinal
substance with or without a suitable diluent”.
They are solid, biconvex or flat in shape and vary in
size, shape and weight which is depends on the
medicaments which are used for preparation. They are
also varying in hardness, disintegration; dissolution
characteristics and thickness depend on their intended
use and method of manufacture. Tablets are the most
widely used solid dosage forms because of their
advantages and popularity increasing day by day.
Tablet usually contains filler, diluents, binders,
lubricants, glidants, disintegrants, antiadherent,
colouring agents and flavouring agents as excipients.

4.  Unpleasant taste can be masked by sugar
coating.
 Provide prolonged stability to medicaments.
 Packing and production is cheap and does not
require more space for storage.
 Easy to divide into halves and quarters whenever
fraction dose is required.
 Cheap, easy to swallow and production does not
require and additional processing steps.
 Unit dosage forms with accurate, stable dose and
great precision and least variability.

5.  Drugs which are amorphous and low density character are
difficult to compress into tablet.
 Hygroscopic drugs are not suitable for compressed
tablets.
 Drugs with low or poor water solubility, sloe dissolution,
high absorbance in GI tract may be difficult to formulate.
 Sensitive to oxygen drugs may require special coating.
 Cost of production may be increase because of coating
and encapsulation to remove bitter and unpleasant taste.
 Some tablet may cause problem in bioavailability.
 Difficult to formulate liquid in tablet and swallowing is
difficult especially for children and ill patients.

6. Three types method of tablet preparation-
[1] Direct compression method
[2] Wet granulation
[3] Dry granulation

7. Some chemicals have free flowing and
cohesive properties so they are enable to
compress directly in a tablet machine without
granulation of it. Some chemicals lacking of
these qualities so some excipients like filler,
disintegrants agents, lubricants and glidants
are used to impart these qualities for
production of tablets by direct compression.

8.  Active drug and other ingredients were
accurately weight.
 Mix all the ingredient thoroughly except
lubricant or glident.
 After that keep the mixture at hot air oven for
10 min for complete drying.
 Then after add the lubricant or glidant
 Punch the tablet by using tablet punching
machine.

9.  Granulation is process in which primary powder
particles are made to form large and these types
of multi particle called granules. In
pharmaceutical industry, granules are useful in
production of tablets and capsules in ranges of
particle size between0.2 to 0.5mm.
 Granulation prevents segregation of constituents
of powder, improve flow ability of powder,
improve compaction characteristics of mixture
and reduce toxic dust.

10. Weighting and blending
Preparation of Damp Mass
Screening Damp Mass into Pellets
and Granules
Drying the granulation
Sizing the granulation by Dry
Screening
Adding Lubrication and
Blending

11.  In this method, powder mixer is compressed
in large pieces and subsequently broken
down or sized into granules. In this method,
either active ingredient or diluent must have
cohesive properties. This method is basically
applied to materials which cannot be
prepared by wet granulation because of
moisture degradation properties or thermo-
mobile properties of granules.

12. It is carried out by two steps:
 Slugging:
After weighing and the mixing of
ingredients, the powder mixture is slugged or
compressed into large flat tablets about one
inch in diameter. Slugs are than broken up
hand or mill and passed through a screen of
desired mess for sizing and sometimes
lubricant are added and prepared by
compression.

13.  Roller compaction:
Instead of slugging, powder compactors
may be used to increase the density of a
powder by pressing it between rollers at 1 ton
to 6 tons of pressure. The compact material
is broken up, sized, and lubricated, and
tablets are prepared by compression.
Commonly used binding agents are methyl
cellulose or hydroxylmethyl cellulose (6-12%)
which produces good hardness and friability
of tablet.

14.  Capping and lamination:
Capping means partial and complete separation of the
top or bottom crowns of a tablet from main body of a
tablet. While lamination is term used to describe the
separation of the two or more distinct layers.
Some reasons which are responsible for these
problems are as follows:
 Air is entrapped among the particles during the
compression process and does not escape until
compression pressure is released.
 Die wall pressure causes enough internal stress to cause a
crack which is due to plastic deformation of the particles
during compaction.
 Sometimes due to deep concave or bevelled edge punches.

15.  Picking:
Picking is the term used to describe the surface
material from tablet that is sticking to being removed
from the tablet's surface by a punch. It concerns
when punching tips have engraving or embossing
 Sticking:
Sticking is usually referred to adhesion of tablet
material to die wall. Because of that, lower punch
cannot move freely and additional force is required to
overcome friction between die wall and the tablet.
These problems can be solved by design large
lettering, adding polishing agent such as colloidal
silica or additional lubricants. Some low melting point
substances such as polyethylene glycol may also
cause sticking at the heat of compression.

16.  Mottling:
Mottling is term used unequal distribution of colour
on a tablet with light and dark areas. It's due to
colour difference of drug with excipients or drugs
whose degradation product is coloured. Such
problems might be solved by using colorants but it
can cause mottling on the top of surface when
granulation undergoes drying. To overcome
difficulties, it require to change solvent system,
binder system and by reducing temperature.