dds tablets

Compressed Tablets (CT)

formed by compression of powdered, crystalline, or

granular materials into the required shape

by the application of high pressures.

compressed tablets that are coated with a colored or an uncolored sugar layer.

Film-coated Tablets (FCT):

compressed

tablets coated with a thin layer of a polymer

capable of forming a skin like film

Enteric-Coated Tablets (ECT)

compressed

tablets coated with substances that resist

solution in gastric fluid but disintegrate in the

intestine.

Multiple Compressed Tablets (MCT):

prepared by subjecting the fill material to more

than a single compression. Can be (a) tablet

within a tablet or (b) multiple-layer table

Chewable Tablets

prepared to have

a smooth, rapid disintegration when

chewed or allowed to dissolve in the

mouth.

Buccal and Sublingual Tablets:

small, flat, oval tablets intended to be

dissolved in the buccal pouch (buccal

tablets) or beneath the tongue

(sublingual tablets) for absorption

through the oral mucosa

Effervescent Tablets:

are prepared by

compressing granular effervescent salts

that release gas when in contact with

water.

Tablet Triturates:

small, cylindrical,

molded or compressed tablets containing

small amounts of potent drugs that are

intended to be readily and completely

soluble in water.

Tablets for Solution (CTS)

Compressed tablets to be used for

preparing solutions. Examples: Halazone

Tablets for Solution and Potassium

Permanganate Tablets for Solutio

Controlled-Release Tablets

Compressed tablets formulated to release the

drug slowly over a prolonged period

Controlled-Release Tablets (CRT):

Effervescent Tablets:

Tablet Triturates:

Tablets for Solution (CTS)

Chewable Tablets

: Buccal and Sublingual Tablets:

Enteric-Coated Tablets (ECT):

Multiple Compressed Tablets

Compressed Tablets (CT)

Sugar-coated Tablets (SCT)

Film-coated Tablets (FCT):

Types of Tablets

Modified Release (extended-release and

delayed-release)

Repeat Action

• Targeted Release

Types of Controlled-Released Tablets

Modified Release Tablets:

drug release features

based on time, course, and/ or location

Extended release:

formulated to make the

contained drug available over an extended period

following ingestion, which allow a reduction in

dosing frequency; called as prolonged action or

sustained - release action

Delayed-release:

designed to release the drug at a

time other than promptly after administration

Repeat-action

contain two single doses of

medication, one for immediate release and the

second for delayed release.

Targeted Release:

drug release directed toward

isolating or concentrating a drug in a body region,

tissue, or site for absorption or for drug action

•Avoid patient compliance problems

•Employ less total drug

•Improve efficiency in treatment

Advantages of Controlled Release

Formulations

Diluents

also known as fillers; added to increase the bulk to

make the tablet a practical size for compression.

Dicalcium phosphate

Calcium carbonate

Celluloses like microcrystalline cellulose

Kaolin

• Dry Starches

Sugars like lactose and sucrose

Sugar alcohols like mannitol, sorbitol, xylitol

Examples of Diluents/Fillers

Binders

Also known as Adhesives

Binders

Agents used to impart cohesive qualities to the

powdered material

dry powders such starch (cornstarch),

gelatin, gums, and sugars (sucrose, glucose, dextrose,

and lactose), microcrystalline cellulose,

polyvinylpyrollidone (PVP); liquid/wet binders such as

water, alcohol, starch paste

binders examples

Glidants

•Improve the flowability of the

powder/granules

Talc (1-2%), Colloidal

Silicon Dioxide (Cab-o-sil, 1% or Less

Glidants examples

Lubricant

They prevent adhesion of the tablet

material to the surface of the dies and facilitate the ejection of the tablets from

the die cavity

Talc, Magnesium stearate,

Calcium stearate, Stearic acid

Lubricants examples

Anti adherents

Used to reduce adhesion between the

powder and the punch faces and thus

prevent particles sticking to the punches.

Magnesium Stearate, Talc,

Starch

Examples anti adherents

Disintegrants

A substance or a mixture of substances added to a

tablet to facilitate its breakup or disintegration after

administration.

starches (pregelatinized starch, 10%),

clays, celluloses (methylcellulose & ethylcellulose),

algins, and gums

Disintegrants examples

cross-linked polymers

(Croscarmellose (2%), crospovidone, and sodium

starch glycolate (5%)

Superdisintegrants examplws

(intragranular addition ).

Disintegrants can be mixed with other

ingredients and incorporated within the

granules

extragranular addition )

It is also

common for the disintegrant to be mixed with

the dry granules before the final granulation is

compacted

• Swelling

• Porosity and

Capillary Action

(Wicking)

• stain recovery

Mechanisms of Disintegrant Action

Stain recovery

mechanical activation

of compacted disintegrant polymer

chains help to partially

recover their original

shapes when they

come in contact with

the aqueous media

Porosity and

Capillary Action

(Wicking)

disintegrant pulls water into the pores

of the tablet and reduces the physical

Bonding forces between particles

Swellimh

particles enlarge omnidirectionally to push apart the adjoining components thereby initiating the breakup of the tablet matrix

Colourants(coloring agents)

are added to tablets to aid

identification and patient compliance.

Flavouring agents

are incorporated into a

formulation to give the tablet a more pleasant

taste or to mask an unpleasant one.

Diluents such as mannitol, lactose,

and sucrose, saccharin (250-500x sweeter),

sodium cyclamate, aspartame (200x sweeter)

Flavouring agents ex

•Wet Granulation

•Dry Granulation

•Direct Compression

Compressed Tablet Manufacture

Three Basic Methods

Slugging,

Roll compaction

DRY GRANULATION methods

Roll compaction

powders are formed into

sheets

Slugging

powders

are formed into tablets or

“slugs

DIRECT COMPRESSION

the process by which tablets are compressed directly from

powdered active drug substance and suitable excipients into a

firm compact without employing the process of granulation.

Direct compression

For chemicals possessing cohesive and free-flowing properties

Potassium Salts, Ammonium Chloride, Methenamine

Direct compression ex

Capping- partial or complete

separation of top or bottom

of tablet

• Lamination- separation of a

tablet into two or more

distinct horizontal layers

• Cracking- small, fine cracks

observed on the upper and

lower central surface of

tablet

Problems with

Direct Compression

Hopper

Feed show

Dies

Punch( lower and upper)

Cam

Main parts of a tablets press machine

Hopper

stores granules or powder

materials for compressing

Feed shoe

delivers and

distributes materials from the hopper

into dies

Dies

where the powder/

granules are compressed into tablets;

controls the size and shape of the tablet

Punch(lower and upper)

compacts

material within the die

Cam

guide the position or movement of

the punches

Single punch press

Rotary press/ multi station press

Types of tablet press

Rotary Press/Multi - station Press

it has several tooling stations which rotates to compress

granules/powder mixture into tablets

Rotary Press/Multi - station Press

Produce up to 10000 tablets per minute

Single-Punch Press

also

known as eccentric press

or single station press

Single-Punch Press-

the simplest machine for

tablet manufacturing as it

uses only a single set of

tableting tools

Single-Punch Press-

Produces up to 200 tablets

per minute

Protect the medicinal agent against destructive

exposure to air and/or humidity

• Mask the taste of the drug

• Provide special characteristics of drug release

• Provide aesthetics or distinction to the product

Tablet Coating

Reasons for Tablet Coating

Waterproofing or

Sealing

2. Subcoating

3. Smoothing

4. Finishing and

coloring if desired

5. Polishing

Sugarcoating Process

Waterproofing or Sealing

Involves hardening the external surface of the tablet by

providing a moisture barrier.

shellac (alcoholic soln),

cellulose acetate phthalate (CAP), polyvinylacetate

phthalate (PVAP), hydroxypropyl methylcellulose

(HPMC), and zein

Waterproofing or Sealing examples

Subcoating

This bonds the sugar coating to the tablet and

provides rounding.

Smoothing and Final Rounding

To complete the rounding and smooth the coatings

thick sucrose-based syrup

Smoothing agent:

Finishing and Coloring

To attain final smoothness and the

appropriate color to the tablets

thin sucrose-based syrup

with coloring agent

Finishing agent: