This document provides an overview of a seminar presentation on tablet preparation and evaluation methods. The presentation covers various tablet types, formulation additives, preparation techniques like wet and dry granulation and direct compression, compression methods using single punch and rotary tablet presses, and quality control tests for tablets including hardness, thickness, friability, dissolution, disintegration, and content uniformity. Evaluation methods and apparatus for each quality control test are also described. The presentation was delivered by Farheen Unnisa to provide guidance on tablet manufacturing and quality testing.

1. A
SEMINAR
PRESENTATION
ON
METHODS OF PREPARATION AND EVALUATION OF
TABLETS
PRESENTED BY
FARHEEN UNNISA
REG.NO.14S61S0307
M.PHARMACY I YR I SEM.
UNDER THE GUIDANCE OF
Mr. KANHU CHARAN PANDA,
M.PHARM,PH.D
ASSISTANT PROFESSOR
ANWARUL-ULOOM COLLEGE OF PHARMACY
(NEW MALLEPALLY, HYDERABAD) 1

2. By
Farheen Unnisa
Tablets
2

3. Scope
Introduction
Types Of tablets
Advantages and Disadvantages
Formulation additives
Preparation of tablets
Tablet compression
Evaluation Of tablets
References
3

4. Introduction
In 1843, a patent was granted to Thomas Brockedon (Englishman) for manufacturing
pills and lozenges.
1980 nearly 300 monographs for tablets.
Over 2/3rd dosage forms are tablets.
Def: Tablets are flat or biconvex discs of unit dosage forms containing one or more active
ingredients, compressed along with necessary additives.
4

5. Types of tablets
 Chewable Tablets
• Easily administered for infants and elderly persons
• These are intended to be chewed in the mouth before swallowing.
Used for large tablet of antacid, bitter or foul testing drugs are not
suitable for this type tablet.
 Effervescent Tablets
Tablets are designed to produce a solution
rapidly with the release of carbon dioxide.
 Troches And Lozenges
These are mainly for treating soar throat and to
control coughing in common cold.
 Soluble tablets
Tablets are intended to be added to a given
volume of water to produce a solution of a given
drug concentration.
5

6.  Buccal And Sublingual Tablets
• Drugs used by this route are for quick systematic
action. The tablets are designed not to be
disintegrate but slowly dissolve.
 Implantation tablets
To provide prolonged drug effects.
used for administration of growth
hormone to food producing animal.
 Film Coated Tablets
• Advantage of film coated over sugar coated tablets
is better mechanical strength and flexibility of the
coating, little increase in tablet weight.
• These are developed as an alternative procedure to the preparation of coated
tablets in which the drug is not required for coating.
 Sugar coated tablet: Primary role is to produce an elegant, glossy,
easy to swallow, widely utilized in preparing multivitamin tablets.
• Sugar coating doubled the tablet weight.
• Now polymers are used with sugar solution.
 Enteric coated tablet: Some drugs are destroyed by gastric juice or
causes irritation to the stomach. These two factors can be overcome
by coating the tablet with cellulose acetate phthalate. 6

7. Advantages
 Production aspect
– Large scale production at lowest cost
– Easiest and cheapest to package and ship
– High stability
 User aspect (doctor, pharmacist, patient)
– Easy to handling
– Lightest and most compact
– Greatest dose precision & least content variability
– Coating can mark unpleasant tastes & improve pt. acceptability
7

8. Disadvantages
 Some drugs resist compression into dense compacts.
 Drugs with poor wetting, slow dissolution, intermediate to large dosages may be
difficult or impossible to formulate and manufacture as a tablet that provide adequate
or full drug bioavailability.
 Bitter taste drugs, drugs with an objectionable odor, or sensitive to oxygen or moisture
may require encapsulation or entrapment prior to compression or the tablets may
require coating.
 Difficult to swallow in case of children and unconscious patients.
8

9. Ingredients used in tablet formulations
Ex: starch
Ex: Acacia
tragacanth
Ex: Methyl
cellulose
Ex: Corn Starch
Ex: Flavor
oils
Ex: metallic
steroids
Ex: Talc
PEG
Ex: MannitolColorant
Ex: Yellow 6
9

10. Tableting methods
• Wet methods
– Wet granulation
• Dry methods
– Dry granulation
– Direct compression
10

11. Tableting methods
11

12. 12

13. 13

14. Compression: Compression is the process of applying pressure to a material with the
help of a Tablet punching machine.
 Transitional repacking/particle rearrangement
 Deformation at point of contact
 Fragmentation and deformation
 Bonding
• Mechanical Theory
• Inter molecular theory
• Liquid –Surface film Theory
 Decompression
 Ejection
TABLET COMPRESSION
14

15. Single punch machine
 The compression is applied by the upper punch making the single punch machine a
“stamping press.”
15

16. Multi-station rotary presses
• The head of the tablet machine holds the upper punches, dies and lower punches in
place rotates
• As the head rotates, the punches are guided up and down by fixed cam tracks,
which control the sequence of filling, compression and ejection.
• The portions of the head that hold the upper and lower punches are called the upper
and lower turrets.
• The portion holding the dies is called the die table
• The pull down cam (C) guides the lower punches to the bottom, allowing the dies to
overfill.
• The punches then pass over a weight-control cam (E), which reduces the fill in the
dies to the desired amount.
16

17. • A swipe off blade (D) at the end of the feed frame removes the excess granulation and
directs it around the turret and back into the front of the feed frame.
• The lower punches travel over the lower compression roll (F) while simultaneously the
upper punches ride beneath the upper compression roll (G).
• The upper punches enter a fixed distance into the dies, while the lower punches are
raised to squeeze and compact the granulation within the dies.
• After the moment of compression, the upper punches are withdrawn as they follow the
upper punch raising cam (H).
• The lower punches ride up the cam (I) which brings the tablets flush with or slightly
above the surface of the dies.
• The tablets strike a sweep off blade affixed to the front of the feed frame (A) and slide
down a chute into a receptacle.
• At the same time, the lower punches re-enter the pull down cam (C) and the cycle is
repeated.
17

18. 18

19. INTRODUCTION
• Quality control, or QC for short, is a process by which
entities review the quality of all factors involved in
production.
19

20. Quality Control Tests Of
TABLETS
20

21. QUALITY CONTROL
TESTS OF
TABLETS
PHYSICAL TESTS CHEMICAL TESTS
3: Friability Test
1: Hardness Test
2: Tablet Thickness
and
Diameter
3: Dissolution Test
1: Content Uniformity 2: Assay
4: Disintegration
Test
5: Weight Variation
Test
21

22. Hardness
• It is defined as the force required to break a tablet in a
diametric compression test.
• Tablet requires a certain amount of strength or hardness
and resistance to friability to withstand mechanical
shakes of handling in manufacture, packaging and
shipping.
• Tablet Hardness Test is performed to
check that the manufactured tablet
is of desired hardness.
22

23. Hardness Testers
1. Strong-Cobb
2. Stokes-Monsanto
3. Eureka
4. Pfizer
Factors Affecting Hardness
• Pressure applied during the compression
• Cohesive forces between ingredients especially binder have
more cohesive forces
• Density
23

24. 1:Strong-Cobb
• The tablet is placed
between two jaws that
crush the tablet.
• The machine measures
the force applied to the
tablet and detects
when it fractures.
24

25. Thickness and Diameter
• Tablet thickness and diameter tests are also very
important qc tests
• Very thick tablet affects packaging either in blister or
plastic container
• The thickness for majority of tablets may vary from
2mm to 4mm
• The diameter of tablets may vary from 4mm to
13mm
25

26. Instruments used
• For diameter: Vernier Calipers
• For thickness: Micrometer Screw Gauge
26

27. Friability
• It is the tendency of tablets to powder, chip, or
fragment and this can affect the elegance appearance,
consumer acceptance of the tablet, and also add to
tablet’s weight variation or content uniformity
problems.
• Friability is a property that is related to the hardness
of the tablet.
• An instrument called friabilator is used to evaluate the
ability of the tablet to withstand abrasion in
packaging, handling, and shipping.
27

28. Friabilator
• Friabilator is a round drum
• It has diameter of 2.87mm and depth of
38mm
• In diameter a horizontal axis is present
• Friabilator is connected to timer to indicate its
rotations
• It is rotated in clockwise direction
28

29. Test Method
• Weigh 20 tab altogether = W1
• Put these tablets in the friabilator and adjust the
instrument at 100 rpm (i.e. = 25 rpm for 4 min)
• Weigh the 20 tablets (only the intact ones) = W2
• The difference between W1 and W2 gives weight loss
(i.e. Friability)
• Weight loss of 1-5% is
acceptable
29

30. Disintegration
• For most tablets , the first important step towards
formation of solution is breakdown of the tablet
into smaller particles or granules , this process is
known as disintegration.
• It is the time required for the tablet to break into
particles, the disintegration test is a measure only
of the time required under a given set of conditions
for a group of tablets to disintegrate into particles
30

31. Disintegration test is performed
with different types of tablets
1. Uncoated tablets
2. Coated tablets
3. Enteric coated tablets
4. Buccal tablets
5. Sublingual tablets
31

32. Disintegration apparatus
The apparatus consists of;
• Basket rack assembly
• A suitable vessel for the immersion liquid
• A thermostatic arrangement for heating the
fluid between 35°C and 39°C
• A device for raising and lowering the basket in
the immersion fluid at a constant frequency
rate between 28 and 32 cpm through a
distance of not less than 5cm and not more
than 6cm
32

33. • BASKET RACK ASSEMBLY:-
It consists of;
• Six open ended glass tubes each 7.75cm long and having an inside
diameter of approximately 21.5mm and a wall 2mm thick
• The tubes are held in a vertical
position by two plastic plates
• Each tube is provided with a
slotted and perforated cylindrical
disk
33

34. Different liquid mediums are used
in disintegration test
• Water
• Simulated gastric fluid (PH= 1.2)
• Simulated intestinal fluid (PH= 7.5)
1: Test method for Uncoated tablets
• Place 1 tablet in each of the 6 tubes of the basket, add a
disk to each tube
• Use water as immersion fluid maintained at 37°C
34

35. • If one or two tablets from the 6 tablets fail disintegrate completely
within 30min repeat the same test on another 12 tablet. (i.e. the
whole test will consume 18 tablets).
• Not less then 16 tablets disintegrate completely within the time
• if more then two tablets (from the 18) fail to disintegrate, the
batch must be rejected.
Factors Affecting Disintegration
• Quantity of disintegrating agent
• Compactness
• Cohesive forces between the ingredients
• Hardness
35

36. Weight Variation
• The actual weight of a tablet is determined by the
diameter of the die and the weight adjustment cam on
the tablet machine
• The weight control on the tablet machine is routinely
adjusted at intervals to ensure that the specified weight is
being reproduced
• This test is perform to ensure uniform distribution of
ingredients throughout batch
36

37. Test Method
• Take 20 tablets
• Weigh individually
• Determine the average weight of 20 tablets
• Compare individual tablet weight to average weight
• Not more than 2 of the individual weights deviate from
the average weight by more than the percentage
deviation
• And none deviates by more than
twice that percentage.
37

38. Weight variation tolerances for uncoated tablets in
U.S.P XVII
Average weight of
Tablet (mg)
Percentage Differences
130 or less 10.0
130-324 7.5
More than 324 5.0
Causes of Weight Variation
1. Poor flow of granules
2. Variation in size of granules due to improper sieving
3. Presence of very fine granules
4. Improper adjustment of machine
5. Improper flow rate 38

39. Dissolution
• The release of drug from the tablet into solution
per unit time under standardize condition is
called dissolution test.
39

40. Dissolution Apparatus
1. Rotating basket method APPARATUS-I
2. Paddle method APPARATUS-II
3. Reciprocating cylinder method APPARATUS-III
4. Flow through cell method APPARATUS-IV
5. Paddle over disk method APPARATUS-V
6. Cylinder method APPARATUS-VI
7. Reciprocating disk method APPARATUS-VII
40

41. 1:Rotating basket method
APPARATUS-I
• The apparatus consists of a cylindrical basket held by
a motor shaft
• The basket holds the sample and rotates in a round
flask containing the dissolution medium
• The entire flask is immersed in a constant
temperature bath set at 37°C
• The rotating speed is 100 rpm
41

42.  The theory and practice of Industrial pharmacy, by Leon Lachmann and
Herbert .A.Lieberman,3rd edition. Page no: 294 to 336.
 Pharmaceutical dosage forms tablet volume-1 edited by Herbert A.Liberman,
Leon Lachman, and Joseph B. Schwartz, page no:88 to 121.
 Pharmaceutical dosage forms tablet volume-2 edited by Herbert A.Liberman,
Leon Lachman, and Joseph B. Schwartz, page no :201 to 211
 Indian pharmacopoeia 2010 vol-2, page No: 751 to 754
 The science and practice of pharmacy by Remington Volume I -905 to 916.
 www.google.com
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