This document discusses tablet manufacturing and quality control. It begins by explaining how direct compression became the most advanced tablet manufacturing technique as it requires fewer steps and less time than older granulation methods. It then describes common excipients used in tablets and the three main manufacturing methods - direct compression, dry granulation, and wet granulation. The mechanisms and components of rotary tablet presses are outlined. Quality control tests for tablets like hardness, thickness, friability, disintegration, weight variation and dissolution are also summarized. References on pharmaceutical manufacturing and quality standards are provided.

1. TABLETS
Manufacturing,
Equipment and Quality
Control.Anirban Saha
M.Pharm (Pharmaceutics)
Semester- 1
Amity University.
AMITY INSTITUTE
OF PHARMACY

2. In early days, most of the tablets required granulation of the powdered
Active Pharmaceutical Ingredient (API) and Excipients. At the
availability of new excipients or modified form of old excipients and the
invention of new tablet machinery or modification of old tablet
machinery provided an ease in manufacturing of tablets by simple
procedure of direct compression.
Amongst the techniques used to prepare tablets, direct compression is
the most advanced technology. It involves only blending and
compression. Thus offering advantage particularly in terms of speedy
production. Because it requires fewer unit operations, less machinery,
reduced number of personnel and considerably less processing time
along with increased product stability.

4.  Lubricants
 To reduce the friction during tablet ejection between
the walls of the tablet and the walls of the die cavity
 Glidants
 Reducing friction between the particles
 To improve the flow properties of the granulations
 Antiadherants
 To prevent adherence of the granules to the punch
faces and dies
o Wetting agents
 Antioxidants
 Preservatives
 Coloring agents
 Flavoring agents

5. Direct compression
Dry granulation
Wet granulation

8.  Hopper for holding and feeding granulation to be
compressed
 Dies that define the size and shape of the tablet
 Punches for compressing the granulation within
the dies
 Cam tracks for guiding the movement of the
punches
 Feeding mechanisms for moving granulation from
the hopper into the dies

10. Mechanism

11. Multi-station rotary presses
The head of the tablet machine that 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 an lower turrets

12.  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
 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)

13.  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

14. Multi Station Rotary Press.

15. Principle- Multi Station Rotary Press.

16.  Although tablet compressing machinery has
undergone numerous mechanical modifications
over the years, the compaction of materials
between a pair of moving punches within a
stationary die has remained unchanged.
 Special adaptations of tablet machines allow for
the compression of layered tablets and coated
tablets.

17. Coating/Polishing:
What are the
problems
What are the
equipment
Why do it
Blistering, chipping,
cratering, picking, pitting
Color variation
Roughness
Pan
(standard/perforated)
Coating Machines
Fluidized Bed Coating
Machines
Spray Coating Machines
Vacuum, Dip &
Electrostatic Coating
Machines
Enhance appearance
and colour
Mask taste and
odour (film/sugar)
Improve patient
compliance
Improve stability
Impart enteric,
delayed, controlled
release properties

18. Tablet Coating Machines

19. In-process Checks :-
Parameter Frequency
Wt. of 20 tabs Every hour by production and every
two hours by QA
Hardness, thickness, length, width Every hour by production, every two
hours by QA
Wt. variation Every half hour by production and
every hour by QA
DT Every half hour by production, every
hour by QA

20. Mixing of
granulation blend
Granulation
Binder(s)
Preparation of
binder solution
Drying
Milling
In Process
Testing
Disintegrant
screening
screening
Initial Blending
lubricant screening Final Blending
Compression
Solvent
Film coating agent Preparation
Film Coating of Tablets
Weight
Hardness
Friability
Complete Process :
Packaging
and Labelling

21. Quality Control of Tablets
General Appearance:
-Size, shape, and thickness:
This is important to facilitate packaging and
to decide which tablet compressing
machine to use.
-Organoleptic properties:
which include color and odor of the tablets.

22. Official Standards as per I.P
Uncoated tablet:
-Uniformity of container content
-Content of active ingredient
-Uniformity of weight
-Uniformity of content
-Disintegration test
Enteric coated tablet:
-Disintegration test

23. Dispersible tablet:
-Uniformity of dispersion
-Disintegration
Soluble tablet:
-Disintegration test
Effervescent tablet:
-Disintegration/ Dissolution / Dispersion
test

24. Official and unofficial tests:
 Non official tests:
Hardness (crushing strength):
It is the load required to crush the tablet
when placed on its edge.
Factors Affecting the Hardness:
 Compression of the tablet and compressive
force.
 Amount of binder. (More binder ,more
hardness)
 Method of granulation in preparing the tablet.

25.  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.
 An instrument called friabilator is used to
evaluate the ability of the tablet to
withstand abrasion in packaging, handling,
and shipping.

26. Procedure:
1. Weigh 20 tab altogether = W1
2. Put these tablets in the friabilator and
adjust the instrument at 100 rpm
3. Weigh the 20 tablets (only the intact ones)
= W2
4. Friability (% loss) = It must be less than or
equal to1% .
But if more we do not reject the tablets as
this test is non-official.

27. Friabilator

28. Thickness Test :
o Thickness is an unofficial test .
o Thickness of the tablet is inversely proportional to hardness i.e.
increase in hardness decrease the thickness & vice versa.
o Thickness of tablet is measured by Vernier caliper.
o It is determined for 10 tablets.
Vernier Caliper

29.  Official Tests:
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.
The time of disintegration is a measure of the
quality. This is because, for example, if the
disintegration time is too high; it means that
the tablet is too highly compressed or is not
of pharmacopoeial quality.

30. Liquids used in disintegration :
 Water,
 Simulated gastric fluid (PH = 1.2 HCl),
 or Simulated intestinal fluid (PH = 7.5)
KH2PO4 (phosphate buffer) + enzyme
+NaOH)
Disintegration Apparatus

31. Limits(Uncoated tablets) :
Medium Temperature Time
limit
According to
U.S.P.
Simulat
ed
gastric
fluid
37°C Not
exceed
30min
According to
B.P.
water 37°C Not
exceed
15min

32. Limits(Coated):

33. Weight Variation (Uniformity of weight) of
tablets:
1. Weigh 20 tablet selected at random, each
one individually . X1, X2, X3… Xz
2. Determine the average weight. X= (X1+X2
+X3+…+ X20)/20
Limits
 Weight of tablet 130 mg or less then %error
= ±10%
 · Weight of tablet 130-324 mg then %error
= ±7.5%
 · Weight of tablet 324 mg or more then
%error = ±5%

34. Dissolution Test
Dissolution is performed to check the percentage release from
the dosage forms i.e.tablet.
Tablet breaks down into small particles which offers a greater
surface area to the dissolving media.
Disintegration test does not give assurance that particles will
release drug in solution at an appropriate rate, that’s why
dissolution tests & it’s specifications developed for all tablet.
Dissolution
Apparatus

35. TYPES OF DISSOLUTION APPARATUS :
1. USP Dissolution apparatus I ( Basket method)
A single tablet is placed in a small wire mesh basket attached to the bottom of the
shaft connected to a variable speed motor. The basket is immersed in a dissolution
medium (as specified in monograph) contained in a 1000 ml flask. The flask is
cylindrical with a hemispherical bottom. The flask is maintained at 37 ± 0.50C by
a constant temperature bath. The motor is adjusted to turn at the specified speed
and sample of the fluid are withdrawn at intervals to determine the amount of
drug in solutions.
USP Dissolution Apparatus I

36. 2. USP Dissolution apparatus II ( Paddle method)
It is same as apparatus-1, except the basket is replaced by a paddle. The dosage
form is allowed to sink to the bottom of the flask before stirring. For dissolution
test U.S.P. specifies the dissolution test medium and volume, type of apparatus to
be used, rpm of the shaft, time limit of the test and assay procedure for. The test
tolerance is expressed as % of the labeled amount of drug dissolved in the time
limit.
USP Dissolution Apparatus II

37. Dissolution testing and interpretation IP standards

38.  Pharmaceutics. The science of dosage forms
design. (M.E. Aulton)
 Leon Lachman, The theory and practice of
Industrial Pharmacy,3rd edition, page no.67-68,77-
78,315-317,296-303.
 Indian Pharmacopoeia-2010,Govt.Of India
ministry of health & family welfare,6th edition.
References