consist introduction and evalution of tablets

1. Introduction of Tablets
&
Evaluation parameters
Submitted to Submitted by
D.r Sonali Singh Pooja Joshi
M.pharm I Sem
Pharmacology

2. CONTENTS
 Definition
 General properties.
 Advantages
 Disadvantages
 Classification of tablets
 Tablet Design and formulation
 Evaluation tests for compressed and coated tablets

3. Defination
 Tablet is defined as a compressed solid dosage form
containing medicaments with or without excipients.
 According to Indian Pharmacopoeia pharmaceutical
tablets are solid, flat, or biconvex dishes, unit dosage
form , prepared by compressing a drugs or a mixture of
drugs, with or without excipients.
 They vary in shape and differ greatly in size and
weight, depending on amount of medicinal substances
and the intended mode of administration.
 It is the most popular dosage form and 70% of the total
medicines are dispensed in the form of tablet.

4. General Properties
 Accurate dosage of medicament , uniform in weight,
appearance and diameter.
 Have the strength to withstand the rigors of
mechanical shocks encountered in its production,
packaging, shipping and dispensing.
 Release the medicinal agents in the body in a
predictable and a reproducible manner.
 Elegant product, acceptable size and shape.
 Chemical and physical stabilities.

5. Advantages
Production aspects
 Large scale production at lowest cost.
 Easiest and cheapest to package and ship.
 Greatest chemical and microbial stability over all
dosage form.
User aspects (doctor, pharmacist,
patient)
 Easy to handling.
 Lightest and more compact.
 Greatest dose precision & least content variability.
 Coating can mask unpleasant tastes & improve
patient acceptability.

6. Disadvantages
 Some drugs resist compression into 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.

7. Classification of tablet
Use
wise
structure
wise
Action
wise
• Tablet for oral ingestion
• In oral cavity
• By other routes
• To prepare solution
• Divisible tablet
• Aperture tablet
• Concave-convex tablet
• Core tablet
• Layered tablet
• Modified release tablet
• Delayed action tablet
 e.g :- enteric coated
Bisacodyl tablet

8. Oral tablet for ingestion
 Standard compressed tablet e.g.; Paracetamol tablet
 Multiple compressed tablet
I. Compression tablet
* Sugar coated tablet
* Film coated tablet
* Gelatin coated tablet
* Enteric coated tablet
II. Layered tablet
III. Inlay tablet
 Targeted tablet
* Floating tablet
* Colon targeting tablet
 Chewable tablet
 Dispersible tablet

9. Tablets used in the oral
cavity
 Lozenges and troches
 Sublingual tablet e.g. vitamin-c tablet
 Buccal tablet e.g. vitamin-c tablet
 Dental cones
 Mouth dissolved tablet/ rapidly dissolving tablet
Tablets administered by other
routes
 Vaginal tablet e.g. clotrimazole tablet
 Rectal tablet
 Hypodermic tablet
 Implants

10. Tablets used to prepare solution
 Effervescent tablet e.g, Disprin tablet (Asprin)
 Molded tablets
* Hypodermic tablets
* Dispensing/ solution tablet e.g, enzyme tablet
(Digiplex)
 Tablet triturates e.g, Enzyme tablet (Digiplex)

11. Standard compression tablet
 These are the standard uncoated tablets made by
either
• direct compression
• wet granulation
• dry granulation
 They may be used for local action in GIT/ systemic
action
 In addition to medicinal agents they usually contain a
number of pharmaceutical adjuvants

12. Multiple compression tablet
I. Compression coated tablet
 Function like sugar-coated or film-coated tablets
or gelatin-coated, enteric coated.
 Coating of a tablet may
• mask a bitter taste, odor, color of the substance
• conceal an unpleasant or mottled appearance
• provide physical and chemical protection from
gastric juice
• control the release of drug from the tablet
* film coated tablet * sugar coated tablet

13. Layered tablet
 Multilayer tablets (2-3) are prepared by repeated
compression of powders and are made primarily to
separate incompatible drugs from each other.
 It makes possible to produce repeat-action or
prolonged-action products.
 for e.g. Admixture containing Phenylephedrine HCL
and ascorbic acid with Paracetamol.
Paracetamol + phenylephedrine HCL——› one layer
Paracetamol + ascorbic acid ——› another layer

14. Targeted tablets
 Under this category we have two types of
tablets:
I. Gastro-retentive tablet
 Opted when API release is desired in
stomach (antacids, API’s used against
H.pylori infection.
• Floating tablet
 to retain the drug for longer time period in
stomach following approaches can be
used:
 low density tablet
 tablet that can expand in gastric
environment(swelling or unfolding).
 Using muco-adhesive polymer.

15. II. Colonic tablets
 For the drugs having poor absorption in stomach or
small intestine, colonic drugs delivery is an answer of
choice.
 The pH of this region varies from 6.4 to 7 and
presence of microbial flora plays an important role in
drug release.
 Various mechanism adopted for drug release in this
area are:
 Coating with Ph sensitive polymer e.g. Eudragit S100
and L 100
 Biodegradable polymer which are sensitive to colonic
bacteria.
 Bio-adhesive polymer e.g. poly

16. Chewable tablets
 Chewable tablets are to be chewed and
thus mechanically disintegrated in the
mouth, so that NO DISINTEGRANT IS
ADDED.
 Flavoring, sweetening and coloring agents
are important.
 Sorbitol and mannitol are common
examples of fillers in chewable tablets.
 Provide quick and complete disintegration
of the tablet and thus obtain a rapid drug
effect after swallowing and dissolution.
 Easy administration, especially for infants
and elderly people.
 Examples: Chewable asprin tablet
 Antacid tablet

17. Dispersible Tablets
 Disintegrate either rapidly in water to form
stabilized suspension or disperse
instantaneously in the mouth to be
swallowed without the aid of water.
 The properties such as porosity, hardness,
DT, increase in viscosity after dispersion
are necessary to investigate during
manufacturing.
 ADVANTAGES
 For pediatric patients who cannot swallow.
 For API’s unstable if formulated in liquid
formulation.
 Faster onset of action compared to
standard compressed tablet.
Example:- Analgesics( Asprin, Ibuprofen,

18. Lonzenges and trouches
 Lonzenges are flavored medicated dosage
forms intended to be sucked and held in mouth
or pharynx.
 Two lonzenges forms include hard (or boiled)
candy lonzenges and compressed tablet
lonzenges (Trouches)
 Lonzenges may be used for:
 Local medications in the mouth and throat,
e.g. local anesthetics, anti-histamines,
decongestion, analgesics, demulcents,
antiseptics & antibiotics.
 Systemic drug uptake
 No disintegrant is included in compressed
lonzenges composition.
 Common binder used:- gelatin, common fillers
are (sorbitol, mannitol, and glucose)

19. Sublingual tablets
 Reguirements of sublingual tablets are
speed of absorption and a
correspondingly rapid physiological
response.
 Intended to be placed beneath the
tongue and held there until absorption
has taken place.
 Absorption through oral cavity, avoids
First pass metabolism .
 Example:- codeine phosphate tablets,
scopolamine HBr tablets, nitroglycerine
tablets etc…

20. Buccal tablets
 Intended to be dissolved in buccal
pouch.
 Tablets are designed not to
disintegrate.
 It is placed near the opening of
parotid duct to provide the medium
to dissolve the tablet.
 Buccal tablets are most often used
when replacement hormonal
therapy is the goal, e.g., methyl
testosterone, testosterone
propionate.

21. Dental cones
 These tablets are designed to be
loosely packed in the empty socket
remaining following a tooth extraction.
 Main purpose behind the use of this
tablet is either to prevent multiplication
of bacteria in the socket by employing a
slow releasing antibacterial compound
or to reduce bleeding by an astringent
or coagulant containing tablet.
 It’s formulated to disslove or erode
slowly in presence of a small volume of
serum or fluid over 20-40 minutes
period.

22. Vaginal tablets
 Designed for vaginal administration in treatment of
local vaginal infections, for systemic absorption and
absorption into vaginal tissue.
 Can be inserted with aid of appliantor
 In the treatment of localized vaginal infections such
as, Candida albicans, yeast and Haemophilus
vaginalis.
 Examples;-
 Cyclodextran formulations of hydrophilic drugs such
as amino-glycosides, beta-lactum antibiotics and
peptides.

23. Implants
 Designed for subcutaneous implantation
by surgical procedure where they are
slowly absorbed over a period of month or
a year.
 Special injector with a hollow needle and
plunger is used to administer the rod
shaped tablet.
 For other shapes surgery is used.
 They are sterile formulation without
excipients.
 Mainly these tablets are prepared to
deliver growth hormones to food producing

24. Effervescent tablets
 Effervescent tablets are dropped into a
glass of water before administration during
which carbon-dioxide is liberated. This
facilitates tablet disintegration and drug
dissolution; the tablet disintegration should
complete within few minutes.
 (Effervescence is a special mech. For
disintegration) carbon-dioxide is created
by the reaction between carbonate or
bicarbonate and a weak acid such as citric
acid or tartaric acid.
 ADVANTAGES
 Rapid drug action e.g. analgesics and
antacids.
 Facilitate drug intake, e.g. vitamins.

25. Hypodermic tablets
 They are intended to be added in WFI of
sterile water to form a clear solution which
is to be injected parenetrally.
 Widely used by rural physician due to its
portability.
 Can be used for medicaments whose
stability in water is very poor
 They use in this manner should be
discouraged. Since resulting solutions are
not sterile.

26. Tablet Triturates
 They are small, usually cylindrical, molded or
compressed tablets containing small amounts of
usually potent drugs.
 Only a minimal pressure is applied during their
manufacturing, since they must be readily and
completely soluble in water.

27. Tablet design and formulation
TABLET DESIGN
 The objective of design & manufacture of the
compressed tablet is to deliver orally the correct
amount of drug in the proper form, at or over the
proper time & in the desired location.
 Aside from the physical or chemical properties of the
medicinal agents, the actual physical design,
manufacturing process, and complete chemical
makeup of the tablet can have a profound effect on
the efficacy of the drug being administerd.

28. Formulation components
 In addition to the active ingredients, tablet contains a
number of inert materials known as additives or
excipients.
 Different types of excipients are :-
 Diluents.
 Binders & Adhesives.
 Disintegrents.
 Lubricants & Glidants.
 Coloring agents.
 Flavoring agents.
 Sweetening agents.

29. Excipients :- functions
 Impart weight, accuracy & volume (it allows accuracy
of dose).
 Improve solubility.
 Increase stability.
 Enhance bioavailability.
 Modifying drug release.
 Increase patient acceptability.
 Facilitate dosage form design.

30. Diluents
 They are used to make required bulk of the tablet
when the drug dosage itself is inadequate to produce
bulk.
 It provide better tablet properties such as improve
cohesion, to promote flow.
 DESIRED PROPERTIES:-
 Non-toxic.
 Cost must be low.
 Commercially available in acceptable grade.
 Must be chemically & physically stable.
 Do not alter the bioavailability of the drug.
 Must be color compatible.

31. Commonly used diluents
 Lactose-anhydrous and spray dried lactose.
 Directly compresssed starch- Sta Rx1500.
 Hydrolyzed starch- Emdex and celutab.
 Microcrystalline cellulose- Avicel (PH 101 & PH 102).
 Dibasic calcium phosphate dehydrate.
 Calcium sulphate dihydrate.
 Mannitol.
 Sorbitol.
 Sucrose- sugartab, DiPac, Nutab
 Dextrose.

32. Binders & Adhesives
 These materials are added either dry or wet-form to
granules or to form cohesive compacts for directly
compressed tablet.
 Example:-
 Acacia, Tragacanth – solution for 10-25% conc.
 Cellulose derivatives- Methyl cellulose, Hydroxy
propyl cellulose.
 Gelatin-10-20% solution.
 Polyvinyl pyrrolidine (PVP)- 2% solution.
 Starch paste- 10-20% solution.
 Sodium Alginate.
 Sorbitol.

33. Disintegrants
 Added to a tablet formulation to facilitate its
breaking or disintegration when it contacts in water
in the GIT.
 Example:-
 Starch- 5-20% of tablet weight.
 Starch derivative- Primogel & Explotab (1-8%).
 Clays- Veegum HV, Bentonite 10% level in colored
tablet.
 Cellulose.
 Alginate.

34. Lubricants & Glidants
 Lubricants are intended to prevent adhesion of the
tablet materials to the surface of dies and punches,
reduce inter particle friction & may improve the rate
of flow of the tablet granulation.
 Glidants are intended to promote flow of granules or
powder material by reducing the friction between the
particles.
 Examples:-
 Lubricants:- stearic acid, mag. Stearate, talc, PEG,
Surfactants.
 Glidants:- corn starch, talc, silica derivatives:-
colloidal silicas, syloid, etc.

35. Coloring Agents
 The use of colors & dyes in a tablet has three
purposes:-
i) Masking of off color drugs
ii) Product identification.
iii)Production of more elegant product.
 All coloring agents must be approved & certified by
FDA.
 Two forms of colors are used in tablet preparation- FD
& C And D&C dyes.
 These dyes are applied as a solution in
the granulating agents or lake form of these dyes.
 Examples:- FD&C yellow 6-sunset yellow, FD&C
Green 3- Fast Green, etc

36. Flavoring agents
 For chewable tablet- flavor oil are used
Sweetning agents
 For chewable tablets: e,g;-mannitol, sugar, etc.
 Saccharine(artificial): 500 times sweeter then
sucrose.
 Aspartame

37. Evaluation test
i) General Appearance.
ii) Organoleptic properties.
iii) Weight Variation.
iv) Content uniformity.
v) Hardness.
vi) Friability.
vii) Dissolution test.
viii) Disintegration test

38. General Appearance
 Size & shape :-
 Thickness : ±5% of standard value.
 Thickness of tablet is measured with a micrometer.
Organoleptic Properties
 Color: color of product must be uniform (no
mottling).
 Instruments used:-
 Reflectance spectrophotometer.
 Tristimulus colorimetry.
 Micro-reflectance photometer.
 odor: (e.g. film coated tablets).
 Taste: (e.g. chewable tablet).

39. Weight Variation
 20 tablets weighed ——› Average individual weight.
 No more than 2 tablets are outside of limit.
IP % USP
Less than 85mg ±10% Weighing 130 mg
or less
85mg-250mg ± 7.5% Weighing 130-
324mg
Greater than
250mg
±5% Weighing 324 mg
or more

40. Content Uniformity
 30 Tablets are selected and 10 are assayed
individually.
 9 of the 10 tablets must contain not less than 85% or
more than 115% of the labeled drug content.
Hardness test
 It is the force required to break a tablet in a diametric
compression also called tablet crushing strength.
 The force required to break the tablet is measured in
kg & usually 4kg is considered to be minimum for
satisfactory tablets.

41. Instruments used
 The Monsanto hardness tester
 The strong- cobb apparatus
 Pfizer tester

42. Friability
 Resistance shown by the tablet during
packaging and transhipment.
 20 tablets are weighed & placed in
apparatus-Roche Friabilator ——›
Revolution at 25 rpm for 4 min(100
revolution) ——› Dropping from 6 inches.
 The tablets are weighed & the weight
compared with the initial weight.
 % Friability =initial weight – final weight x
100
initial weight
 limit :- 0.5-1%

43. Dissolution test
 It is defined as the amount of
drug substance that goes into
solution per unit time under
standardized conditions of
liquid/solid interface,
temperature and solvent
composition.
 It is carried out in:-
i) USP dissolution apparatus
type I (basket type)
ii) USP dissolution apparatus
type II (Paddle type)

44. Disintegration test
 6 test tubes & 3 inch long ——› 10 mesh
screen —› 1L beaker of water(0.1N HCL)
simulated gastric fluid or simulated
intestinal fluid ——› temp 37±2ºC ——› up
& down from 5-6 cm ——› Frequency- 28-
32 cycle/minute.
 tablet should remain 2.5 cm below the
surface of liquid on their upward
movement & same for downward
movement.
 uncoated tablets:- as low as 5 min
 Majority of tablets has disintegration time
of 30 min.
 Enteric coated:- simulated gastric fluid:-
no evidence of disintegration after one
hour.
simulated intestinal fluid:-

45. Quality control of coated tablet
 After coating, the tablets should be inspected &
tested for appearance such as color, size & any
physical defects.
 In-vitro performance of the coated product is
evaluated by disintegration & dissolution testing.
 Crushing strength of coated tablets can be
determined with the tablet hardness tester.
 Adhesion tests with tensile-strength testers have
been used to measure the force required to peel
the film from the tablet surface.
 Additional testing of coated tablets may also
includes tests for resistance to chipping & cracking
during handling.
 METHODS & DEVICES FOR THESE
TESTS ARE SIMILAR TO THOSE USED FOR
UNCOATED TABLETS.

46.  Lieberman’s Lachman;”The theory and practice
of Indusdtrial Pharmacy”,CBS publishers &
distributors pvt ltd, fourth edition, pp:- 449-522