GENERAL TIPS
Types of Tablet:IP
Uncoated
Film Coated
Enteric Coated
USP
Compressed/molded
Plain Coated
Delayed Release
Dispersible Tablet
Modified Release Tablet
Soluble Tablet
Effervescent Tablet
For use in mouth
(Chewable, Lozenges,
Sublingual)
Orodispersible
BP
Uncoated
Coated
Gastro Resistent (Enteric
Coated)
Dispersible Tablet
Modified Release Tablet
Soluble Tablet
Effervescent Tablet
For use in mouth
(Chewable, Lozenges,
Sublingual)
Orodispersible
Standards for Tablets:IP
Content of Active
Ingredient
Uniformity of weight
Uniformity of Content
DT
Dissolution
BP
Content of Active
Ingredient
Uniformity of weight
Uniformity of Content
DT
Dissolution
USP
Content of Active
Ingredient
Weight Variation
Uniformity of Content
DT
Dissolution
Dispersible Tablet
Exteded Release Tablet
Soluble Tablet
Effervescent Tablet
Chewable/Buccal,
Sublingual
Orodispersible
1) Content of Active Ingredient: - 1) Assay of Active
2) 20 tabs: - Limits 90% to 110%
2) Uniformity of Weight/Wt Variation:20 tabs, calculate avg. wt NMT 2 deviate, none twice the limits.
Weight Variation Limits:1) For Tablets
IP/BP
Limit
80 mg or less
10%
More than 80mg or 7.5%
Less than 250mg
USP
130mg or less
130mg to 324mg
250mg or more
More than 324mg
5%
2) For Capsule:IP
Less than 300mg
300mg or More
Limit
10%
7.5%
Friability Test:- This test is additional to check crushing strength of tablet by this test
one can check Capping &/or Lamination. USP limit is 0.5 to 1%. Rotation: - 25 rpm or
100 rotations in 4 min.
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USP 29-now <905>Uniformity of Dosage Units
≥ 25 mg & 25% of active
ingredient
Uniformity of Content or Content Uniformity:IP: - Active less than 10mg or 10%,
BP:- Active less than 2 mg or 2%,
USP:- Active less than 25mg or 25%.
-10 tabs limit NMT 1 tab deviate 85 – 115% & none outside 75 – 125% of the Avg
value/IP/BP/USP (Relative Standard Deviation less than or equal to 6%),
- If 2 or 3 individual values are outside the limits 85 – 115% of the Avg value, & none
outside 75 – 125% repeat for 20 tabs.
- Complies when 30 tabs NMT 3 of the individual values are outside the limit 85 – 115%
of the Avg value, and none outside 75 – 125%.
Disintegration Time:NMT 15 min, in water with Disc 370C ± 20C
Uncoated Tablet
NMT 30 min, In water with Disc for Film Coated Tab, and
Coated Tablet
NMT 60 min Other than Film coated tablet
Intact for 1 hr in 0.1 N HCl & disintegrate within 2 hr in Mixed
Enteric Coated Tab
6.8 Phosphate buffer. According to USP 1 hr in Simulated
gastric fluid, then in Simulated Intestinal Fluid.
Within 3 min in water at 250C ± 10C (IP) & 15 – 250C (BP)
Dispersible/Soluble
Within 1 min
Orodispersible
5 min in 250 ml water at 20 – 300C (IP) & 5 min in 200 ml
Effervescent Tab
water at 15-250C (BP)
Buccal & Sublingual Not Applicable but dissolve within 15 – 30 min.
DT Apparatus:- Mesh Apperture:- 2mm (#10), Cycles:- 28 – 32 cycles/min, 50 – 60 mm
distance from bottom & top, Temp of water 370C ± 20C. If 1 or 2 tabs fail, repeat for 12
tabs.
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Solubility:-
BP SOLUBILITIES
Very soluble
less than 1 part
Freely soluble
from 1 to 10 parts
Soluble
from 10 to 30 parts
Sparingly soluble
from 30 to 100 parts
Slightly soluble
from 100 to 1000 parts
Very slightly soluble
from 1000 to 10,000 parts
Practically insoluble
more than 10,000 parts
Approximate quantity of solvent by volume for one part of soluble
by weight. For example, 1g of a very soluble substance dissolves
in less than 1ml of solvent (1gm/ml).
Compressibility Index (Carr’s Index):Tapped Density – Bulk Density x 100
Tapped Density
Flow property
Excellent
Good
Fair
Passable
Poor
Very poor
Very, very poor
C.I (%)
≤10
11 – 15
16 – 20
21 – 25
26 – 31
32 – 37
>38
Flow property
Excellent
Good
Fair-aid not needed
Passable – may hang up
Poor – must agitate,
vibrate
Very poor
Very, very poor
Angle of Repose:θ = tan-1(h/r)
Hausner ratio
1.00 – 1.11
1.12 – 1.18
1.19 – 1.25
1.26 – 1.34
1.35 – 1.45
1.46 – 1.59
>1.60
Angle of repose (degrees)
25 – 30
31 – 35
36 – 40
41 – 45
46 – 55
56 – 65
>66
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Bioavailability:- The rate and extent to which the active ingredient or active moiety is
absorbed from a drug product and becomes available at the site of action. For drug
products that are not intended to be absorbed into the bloodstream, bioavailability may be
assessed by measurements intended to reflect the rate and extent to which the active
ingredient or active moiety becomes available at the site of action.
ANDA - Abbreviated New Drug Application.
IND – Investigational New Drug Application.
NDA – New Drug Application.
According to the BCS, drug substances are classified as follows:
Class I - High Solubility, High Permeability
Class II - High Permeability, Low Solubility
Class III -High Solubility, Low Permeability
Class IV - , Low Solubility Low Permeability
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A drug substance is considered HIGHLY SOLUBLE when the highest dose
strength is soluble in < 250 ml water over a pH range of 1 to 7.5.
A drug substance is considered HIGHLY PERMEABLE when the extent of
absorption in humans is determined to be > 90% of an administered dose, based
on mass-balance or in comparison to an intravenous reference dose.
A drug product is considered to be RAPIDLY DISSOLVING when > 85% of the
labeled amount of drug substance dissolves within 30 minutes using USP
apparatus I or II in a volume of < 900 ml buffer solutions.
DISSOLUTION DETERMINATION
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
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USP apparatus I (basket) at 100 rpm or USP apparatus II (paddle) at 50 rpm.
Dissolution media (900 ml): 0.1 N HCl or simulated gastric fluid, pH 4.5 buffer,
and pH 6.8 buffer or simulated intestinal fluid.
Compare dissolution profiles of test and reference products using a similarity
factor (f2).
AN ARRAY OF TABLET TYPES
Immediate Release Uncoated Tablets: Usually no taste/stability issues.
Coated Tablets: For taste/stability/identification (coated with water-soluble/dispersible
polymer–mixture of hydroxypropyl cellulose/hydroxypropylmethyl cellulose); coating
readily ruptures in GI tract.
Enteric-Coated Tablets: For drugs inactivated or destroyed in the stomach or for those
causing irritation to the gastric mucosa; tablet passes through the stomach but
disintegrates in the intestines where absorption takes place. Excipients used for enteric
coating include cellulose acetate phthalate, mixtures of fats and fatty acids, etc.
Multiple Compressed Tablets: Multiple-layered tablets manufactured by using more
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than one compression cycle. Each layer contains a different drug and each may be
colored differently.
Controlled Release Tablets: Improved therapy, less toxicity, improved patient
compliance—using polymers such as methacrylates.
Sublingual Tablets: Small, flat ovals such as nitroglycerin. They are ideal tablets for
absorption of drugs which are destroyed by gastric juice or undergo first pass
metabolism.
Chewable Tablets: Disintegrate rapidly when chewed for patients with swallowing
difficulty (children, elderly) and when there is no access to water. Most commonly used
for multiple vitamins and antacids.
Effervescent Tablets: In addition to the active, this product form contains sodium
bicarbonate and citric acid. When water is added the ensuing chemical reaction forms
carbon dioxide, which acts as a disintegrant and produces effervescence that hastens
dissolution (antacids).
Official Standards as per I.P. / B.P. / U.S.P.
COMPARISON OF DIFFERENT PHARMACOPOEIAL QUALITY CONTROL
TESTS
PHARMACOPOEIAS
TYPE OF
TABLET
TESTS TO BE PERFORMED
Content of active ingredients
For all tablets
Uncoated tablet
BRITISH
PHARMACOPOEIA
Effervescent tablet
Coated tablet
Gastro resistant
tablet
Modified release
tablet
Tablet for use in
mouth
Disintegration
Uniformity of content
Labeling
Disintegration test
Uniformity of weight
Disintegration test
Uniformity of weight
Disintegration test
Uniformity of weight
Disintegration test
Uniformity of weight
Uniformity of weight
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Soluble tablet
Dispersible tablet
Disintegration test
Uniformity of weight
Disintegration test
Uniformity of dispersion
Uniformity of weight
Uniformity of container content
Uncoated tablet
Content of active ingredient
Uniformity of weight
Uniformity of content
Disintegration test
INDIAN
PHARMACOPOEIA
Enteric coated tablet Disintegration test
Dispersible tablet
Soluble tablet
Effervescent tablet
UNITED STATES
PHARMACOPOEIA
Physical tests
applicable to tablet
formulation
Uniformity of dispersion
Disintegration
Disintegration test
Disintegration/ Dissolution /
Dispersion
test
Bulk density /Tapped density of
powder
Powder fineness
Loss on drying
Disintegration test
Tablet friability
Dissolution test
Drug release testing
Uniformity of dosage form
Container permeation test
Labeling of inactive ingredients
Tablet Problems:Capping:- ‘Capping’ is the term used, when the upper or lower segment of the tablet
separates horizontally, either partially or completely from the main body of a tablet and
comes off as a cap, during ejection from the tablet press, or during subsequent handling.
Lamination / Laminating:- Definition: ‘Lamination’ is the separation of a tablet into
two or more distinct horizontal layers.
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Chipping:- ‘Chipping’ is defined as the breaking of tablet edges, while the tablet leaves
the press or during subsequent handling and coating operations.
Cracking:- Small, fine cracks observed on the upper and lower central surface of
tablets, or very rarely on the sidewall are referred to as ‘Cracks’.
Sticking / Filming:- ‘Sticking’ refers to the tablet material adhering to the die wall.
Filming is a slow form of sticking and is largely due to excess moisture in the
granulation.
Picking:- ‘Picking’ is the term used when a small amount of material from a tablet is
sticking to and being removed off from the tablet-surface by a punch face.
The problem is more prevalent on the upper punch faces than on the lower ones. The
problem worsens, if tablets are repeatedly manufactured in this station of tooling because
of the more and more material getting added to the already stuck material on the punch
face.
Mottling:- ‘Mottling’ is the term used to describe an unequal distribution of colour on a
tablet, with light or dark spots standing out in an otherwise uniform surface.
Double impression:- ‘Double Impression’ involves only those punches, which have a
monogram or other engraving on them.
Problems for tablet coating:Blistering:- It is local detachment of film from the substrate forming blister.
Chipping: It is defect where the film becomes chipped and dented, usually at the edges
of the tablet.
Cratering: It is defect of film coating whereby volcanic-like craters appears exposing the
tablet surface.
Picking: It is defect where isolated areas of film are pulled away from the surface when
the tablet sticks together and then part.
Pitting: It is defect whereby pits occur in the surface of a tablet core without any visible
disruption of the film coating.
Blooming: It is defect where coating becomes dull immediately or after prolonged
storage at high temperatures.
Blushing: It is defect best described as whitish specks or haziness in the film.
Colour variation: A defect which involves variation in colour of the film.
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Infilling: It is defect that renders the intagliations indistinctness.
Orange peel/Roughness: It is surface defect resulting in the film being rough and
nonglossy. Appearance is similar to that of an orange.
Cracking/Splitting: It is defect in which the film either cracks across the crown of the
tablet (cracking) or splits around the edges of the tablet (Splitting).
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