A PRESENTATION
ON
TABLET AND ITS
FORMULATION
DV BHOOMI INSTITUTE OF PHARMACY AND RESEARCH, DEHRADUN
UTTARAKHAND TECHNICAL UNIVERSITY, DEHRADUN, UTTARAKHAND, INDIA
Dr. TULSI BISHT
B.Pharma, M.Pharma, Ph.d
•Associate Professor
•Department of pharmaceutical
sciences
•Dev Bhoomi Group Institute
(DBGI)
•Dehradun, Uttarakhand
Advantages of Tablet DosageForm
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
Disadvantages of Tablet
Difficult to swallow in case of children and
unconscious patients.
Some drugs resist compression into dense
compacts, owing to amorphous nature, low
density character.
Drugs with poor wetting, slow dissolution
properties, optimum absorption high in GIT may
be difficult to formulate or manufacture as a
tablet that will still provide adequate or full drug
bioavailability.
Bitter testing drugs, drugs with an objectionable
odor or drugs that are sensitive to oxygen may
require encapsulation or coating. In such cases,
capsule may offer the best and lowest cost.
Different Types oftablets
(A)Tablets ingested orally:
1.Compressed tablet, e.g. Paracetamol tablet
2.Multiple compressed tablet
3.Repeat action tablet
4.Delayed release tablet, e.g. Enteric coated
Bisacodyltablet
5.Sugar coated tablet, e.g. Multivitamin tablet
6.Film coated tablet, e.g. Metronidazole tablet
7.Chewable tablet, e.g. Antacid tablet
(B)Tablets used in oral cavity:
1.Buccal tablet, e.g. Vitamin-c tablet
2.Sublingual tablet, e.g. Vicks Menthol tablet
3.Troches or lozenges
4.Dental cone
(c)Tabletsadministered by other route:
1.Implantationtablet
2.Vaginal tablet, e.g. Clotrimazoletablet
(D) Tablets used to preparesolution:
1. Effervescent tablet, e.g. Dispirintablet(Aspirin)
2. Dispensing tablet, e.g. Enzymetablet (Digiplex)
3.Hypodermictablet
4.Tablet triturates e.g. Enzyme tablet(Digiplex)
TabletIngredients
In addition to active ingredients, tablet contains
a number of inert materials known as additives
or excipients. Different excipients are:
Diluent
Binder and adhesive
Disintegrents Lubricants
and glidants Colouring
agents Flavoring agents
Sweetening agents
Properties ofDiluents
1.They must be non toxic.
2.They must be commercially available in acceptable
grade
3.There cost must be low
4.They must be physiologically inert
5.They must be physically & chemically stable by
themselves & in combination with the drugs.
6.They must be free from all microbial
contamination.
7.They do not alter the bioavailability of drug.
8.They must be color compatible.
C.Disintegrates
Added to a tablet formulation to facilitate its breaking or
disintegration when it contact in water in the GIT.
Example:
•Starch-5-20% of tablet weight.
•Starch derivative –Primogel and Explotab (1-8%)
•Clays-Veegum HV, bentonite 10% level in colored tablet only
•Cellulose
•Cellulose derivatives-Ac-Di-Sol (sodium carboxy methyl
cellulose)
•Alginate
•PVP (Polyvinylpyrrolidone), cross-linked
D.LUBRICANTS
Lubricant is a substance capable of reducing or preventing
friction, heat, and wear when introduced as a film between
solid surfaces. It works by coating on the surface of particles,
and thus preventing adhesion of the tablet material to the dies
and punches.
Glycerylmonostearate(USP/NFCH2(OH)CH(OH)CH2O2
CC17H35) is one example of a lubricant. Lubricants play
more than one role in the preparation of tablets as described
below.
1. Lubricants improve the flow of granules in the hopper to
the die cavity.
2.Lubricants prevent sticking of tablet formulation to the
punches and dies during formulation.
3.Lubricants reduce the friction between the tablet and the
die wall during the tablet’s ejection from the tablet machine.
4. Lubricants give a sheen to the finishedtablets.
Commonly used lubricants include: talc,
magnesium stearat, calcium stearate
,stearic acid, hydrogenated vegetable oils and
(PEG).
Compressed tabletmanufacture
•The classification of manufacturingmethods
wet granulation: suitable for drugs that are stable to
moisture and heat
dry granulation: suitable for drugs that are sensitive to
moisture and heat
powder compression : suitable for drugs that are sensitive to
moisture and heat, fill material possessing, good flowability
and compressibility
granulation
direct
compression
crystal compression :suitable for drugs with
proper crystal form and good flowability
The steps of wetgranulation
(liquid
binder)
Internal
External
The classification of tabletpresses
Tabletpresses:
a.single-punchpresses
b.multi-station rotarypresses
The main components of single-punch
tablet presses
Corecomponents:
•die
•lowerpunch
•upperpunch
The basic mechanical process of tableting with
single-punch presses
a)filling material
b)scraping away the excessive
granulation
c)forming a tablet by compression
d)pushing up the tablet to stage
surface
e)shoving the tablet aside
A picture of multi-station rotarypress
hopper
head: upper turret, lower turret,
die table upper turret
Die table lower turret
The core components and compression
cycle of rotary presses
A: upper punch B: die cavity
C: die
D: lower punch
The compression is applied by both the upper punch and the lower punch.
The compression cycle of a rotary tablet press
Direct compressiontableting
Suitable for
1) granular chemicals possessing free flowing and
cohesive properties
e.g. potassium chloride
2) chemicals added with special pharmaceutical
excipients which impart the necessary qualities for the
production of tablets by direct compression
The direct compression tableting excipients include:
a) fillers, as spray-dried lactose, microcrystals of alphamonohydrate
lactose, sucroseinvert ,sugar –corn starch mixtures,
microcrystalline cellulose, crystalline malt and dicalcium
phosphate;
d) disintegrants, as direct-compression starch, sodium
carboxymethyl starch, cross-linked carboxymethylcellulose fiber,
and cross-linked polyvinylpyrrolidone;
c)lubricants, as magnesium stearate and talc;
d)glidants, fumed silicon dioxide
Processingproblems
Cappingisthepartialorcompleteseparationofthetop
orbottomcrownsofatabletfromthemainbodyofthe
tablet.
Laminationis separation of a tablet into two or more
distinct layers. Both of these problems usually result
from air entrapment during processing.
Pickingis removal of a tablet’s surface material by a
punch.
Stickingisadhesionoftabletmaterialtoadiewall.
Thesetwoproblemsresultfromexcessivemoistureor
substanceswithlowmeltingtemperaturesinthe
formulation
Tabletcoating
The reasons for tablet coating
1)to protect the medicinal agent against destructive
exposure to air and/or humidity;
2)to mask the taste of the drug;
3)to provide special characteristics of drug release;
4)to provide aesthetics or distinction to the product;
5)to prevent inadvertent contact by nonpatients with the
drug substance
The general methods involved in coating
tablets are as follows
1)sugarcoating tablets
2)film-coating tablets
3)enteric coating
4)pan coating
5)fluid-bed or air suspension coating
6)compression coating
The sugarcoating of tablets may be divided into the
following steps:
1)waterproofing and sealing (if needed)
2)subcoating
3)smoothing and final rounding
4)finishing and coloring (if desired)
5)polishing
b)When the tablets are partially dry they are sprinkled with a
dusting powder, usually a mixture of powdered sugar and
starch but sometimes talc, acacia, or precipitated chalk as
well.
c)Then drying the tablets. Repetition (15 to 18 times) the
subcoating process until the tablets are of the desired shape
and size.
2)smoothing and final rounding
aim: to complete the rounding and smooth the coatings 5 to 10
additional coatings of a thick syrup; This syrup is
sucrose-based with or without additional components as
starch and calcium carbonate.
4)finishing and coloring
aim: to attain final smoothness and the appropriate color several
coats of a thin syrup containing the desired colorant
5)imprinting
aim: to impart identification codes and other distinctive symbols to the
product
The imprint may be debossed, embossed, engraved, or printed on the
surface with ink.
6)polishing
aim: to render the tablets the desired sheen/gloss/luster
a)pans lined with canvas cloth impregnated with carnauba waxand/or
beeswax
b)Pieces of wax may be placed in a polishing pan
c)light-spraying of the tablets with wax dissolved in a nonaqueous
solvent
Film-coating
1)The disadvantages of sugarcoating process
a)time-consuming
b)requiring the expertise of highly skilled technicians
c)doubling the size and weight of the original uncoated
tablets
d)may vary in size from batch to batch and within a
batch
e)large tablets are not as easily swallowed as are small
tablets.
2)The advantages of film-coating process
a)coated tablets having essentially the same weight, shape, and
size as the originally compressed tablet
b)The coating is thin enough to reveal any identifying
monograms.
c)far more resistant to destruction by abrasion than are
sugar-coated tablets
d)the coating may be colored to make the tablets attractive and
distinctive.
3)The components of nonaqueous film-coating solutions:
a)film former: e.g. CAP
b)alloying substance: to provide water solubility or permeability to the
film e.g. PEG
c)plasticizer: to render flexibility and elasticity to the coatinge.g.
castor oil
d)surfactant: to enhance spreadability of the film e.g. polyoxyethylene
sorbitan derivatives
e)opaquants and colorants: e.g. titanium dioxide, FD&C or D&C dyes
f)sweeteners, flavors, and aromas: saccharin, vanillin
g)glossant: beeswax
h)volatile solvent: alcohol-acetone mixture
4)The components of a typical aqueous film-coating
solutions:
a)film-forming polymer (7-18%): e.g. cellulose
ether polymers as HPMC, HPC and MC
b)plasticizer (0.5-2.0%): e.g. glycerin, propylene glycol,
PEG, diethyl phthalate, and dibutyl subacetate
c)colorant and opacifier (2.5-8%): FD&C or D&C lakes
and iron oxide pigments
d)water
5)Some problems with aqueous film-coating
a)picking and peelingthe appearance of small amounts or large amounts
of film fragments flaking from the tablet surface
b)orange peel effectroughness of the tablet surface due to failure of
spray droplets to coalesce
c)mottlingan uneven distribution of color on the tablet surface
d)bridging
filling-in of the score-line or indented logo on the tablet by the film
e)tablet erosion
disfiguration of the core tablet
The reasons for capping,
splitting or laminating of
tablets
1)air entrapment
2)not immaculately cleaned or not perfectly
smoothed punches
3)too great a proportion of fine powder
4)Tablets have aged or have been stored
improperly
Quality standards and compendial
requirements
The apparent physical features of compressed tablets:
1) shape: round, oblong, unique2) thickness: thick or thin
3) diameter: large or small4) flat or convex
5)unscored or scored in halves, thirds and quadrants
6)engraved or imprinted with an identifying symbol and/or code number
7)coated or uncoated8)colored or uncolored9) number of
layer.
The dieand punches determine the physical features of compressed
tablets.
Quality standards and compendial
requirements
Other physical specifications and quality
standards:
weight variation
tablet thickness tablet
disintegration
tablet weight
content uniformity
tablet hardness
drug dissolution
in-processcontrols
verification after theproduction
Quality standards and compendialrequirements
——tablet weight and Chp weightvariation
Chp weight variation:
sample amount 20
tablets
Tablets should comply
with the following
requirements stated in
the table below.
Average
weight
Lessthan
0.3g
Weight
variation
limit
±7.5%
0.3 g or
more
±5%
Quality standards and compendialrequirements
——tablet weight and Chp weightvariation
The procedure of weight variation determination in Chp:
Weigh accurately 20 tablets and calculate the average weight,
then weigh individually each of the 20 tablets. Compare the
weight of each tablet with the labelled tablet (if no labelled
weight is stated, compare the weight of each tablet with the
average weight calculated). No more than 2 of the individual
weights exceed the weight variation limit stated in the table
above and none doubles the limit.
Quality standards and compendialrequirements
——tablet hardness andfriability
Tablet hardness
1)The greater the pressure applied, the harder the tablets.
2)The hardness required by different tablets
a)lozenges and buccal tablets: hard (dissolve slowly)
b)the tablets for immediate drug release: soft
3)measurement
a)special dedicated hardness testers
b)multifunctional equipment
Quality standards and compendialrequirements
——contentuniformity
Applys to potent drug of lowdose.
USP method, 10 tablets are individually assayed for
their content.
The amount of active ingredient in each tablet lies within
the range of 85% to 115% of the label claim and the
RSD is less than 6.0%.
Quality standards and compendialrequirements
——tabletdissolution
1)The importance of in vitro dissolution test
a)to guide the formulation and product development process
toward product optimization
b)to monitor the performance of manufacturing process
c)toassurebioequivalencefrombatchtobatch
d)asarequirementforregulatoryapprovalforproduct
marketingforproductsregisteredwiththeFDAand
regulatoryagenciesofothercountries.
2)Thegoalofinvitrodissolutionistoprovidea
reasonablepredictionoftheproduct’sinvivo
bioavailability.
Basis: The combinations of a drug’s solubility and its
intestinal permeability are supposed as a basis for
predicting the likelihood of achieving a successful
in vivo –in vitro correlation (IVIVC).
Considered are drugs determined to have:
a)high solubility and high permeability (IVIVC
may be expected.)
b)low solubility and high permeability (IVIVC may
be expected.)
c)high solubility and low permeability
d)low solubility and low permeability
3)The formulation and manufacturing factors affecting the
dissolution of a tablet
a)the particle size of the drug substance
b)the solubility and hygroscopicity of the formulation
c)the type and concentration of the disintegrant, binder,
and lubricant used
d)the manufacturing method, particularly, the
compactness of the granulation and the compression
force
e)the in-processvariables
4)Test method
a)A volume of the dissolution medium is placed in the
vessel and allowed to come to 37℃±0.5℃.
b)The stirrer is rotate at the specified speed.
c)At stated intervals, samples of the medium are
withdrawn for chemical analysis
5)Requirement for rate of dissolution
The specific required rates of dissolution are different for
tablets containing different medicinal agents.
e.g. not less than 85% of the labeled amount is dissolved in 30
minutes
6) Inconsistencies in dissolution
occur not between dosage units from the same production batch,
but rather between batches or between products from different
manufacturers.
Pooleddissolutiontestinghasemerged.Thisprocessrecognizes
theconceptofbatchcharacteristicsandallowspooled
specimenstobetested.