Tablet Formation

Question 1

4 methods of tablet manufacturing

Answer 1

Wet granulation

Dry granulation - slugging

Roller compaction - also dry

Direct compression

Question 2

What is wet granulation

Answer 2

Mixing API with excipients and a wet binder to form granules which are then dried

Question 3

What is wet granulation suitable for and what does it achieve

Answer 3

Drugs with poor solubility and flow properties

Enhances uniformity of drug distribution and improves compression characteristics

Question 4

What is dry granulation

Answer 4

Compacts drugs and excipients under high presssure to form slugs which are milled into granules

Question 5

What is dry granulation used for and what does it achieve

Answer 5

Used when a drug cannot withstand heat or moisture

Simpler and less expensive than wet but requires drugs and excipients with cohesive properties

Question 6

What is roller compaction

Answer 6

A dry granulation technique where powder particles are made to adhere under high pressure between two counter-rotating rollers.

Question 7

What is roller compaction used for

Answer 7

useful for moisture- sensitive drugs. It is efficient and eliminates the need for binders or liquids.

Question 8

What is direct compression

Answer 8

The simplest method, where the drug and excipients are blended and compressed into tablets without prior granulation.

cost- effective and efficient but requires the drug and excipients to have excellent flow and compression characteristics.

Question 9

Factors that determine the choice of manufacturing process

Answer 9

Compression Properties of the Therapeutic Agent

Particle size of therapeutic agent

Types of Excipients

Chemical Stability of the Therapeutic Agent

Question 10

What is Compression Properties of the Therapeutic Agent

Answer 10

The ability of the drug to form a compact mass under pressure is crucial.

Drugs with good compressibility can be easily formulated using direct compression

drugs with poor compressibility, alternative methods such as wet granulation may be necessary

Question 11

What is Particle size of therapeutic agent

Answer 11

The size of drug particles affects the dissolution rate, bioavailability, and homogeneity of the tablet. Smaller particles may enhance dissolution but can pose challenges in flowability and uniform mixing.

Question 12

What is Types of Excipients

Answer 12

The compatibility of excipients with the drug and the desired release profile dictates the choice of excipients the manufacturing process.

For instance, moisture- sensitive drugs may benefit from dry granulation or direct compression to avoid exposure to water during wet granulation.

Question 13

What is Chemical Stability of the Therapeutic Agent

Answer 13

The stability of a drug under various conditions influences the manufacturing process.

Processes that involve heat or moisture may not be suitable for thermolabile or hydrolytic drugs,

Question 14

General steps in manufacturing of tablets

Answer 14

1. Mixing of API with the excipients
2. Granulation of the mixed powder
3. Mixing of powder or granules with other excipients
4. Compression of the powder / granule mixture into tablet

Question 15

What part of the process is the drug added

Answer 15

Milling

Question 16

What part of the process is the excipient added

Answer 16

Blending

Question 17

What part of the process is the binder solution added

Answer 17

Wet granulation

Question 18

What part of the process is the lubricant added

Answer 18

2nd blending after sieving

Question 19

Types of excipient

Answer 19

Diluent/filler
Binder
Disintergrant
Lubricant
Glidant
Absorbent
Sweetening agent
Colouring agent
Surface active agent

Question 20

Diluent/filler

Answer 20

Added in all manufacturing processes

Added to increases mass/bulk of tablet containing low conc of therapeutic agent

Eg. Anhydrous lactose - used in wet and dry
Eg. Spray dried lactose - used in direct compression
Eg. Starch - used as a liquid diluent
Eg. Mannitol - used in chewable tablets

Question 21

Binders

Answer 21

Polymeric components
Mainly used in wet granulation
Can be added as solution or powder
Holds components together

Question 22

Disintergrants

Answer 22

1st mechanism - Added to tablet formation to facilitate breakdown of tablet upon entry to stomach
Disintegration must occur within 15mins

Eg. Starch and MCC

2nd mechanism - Can also occur by swelling in presence of aqueous fluids, increasing the nternal pressure with the tablet

3rd mechanism - gas formation - effervescent tablets

Question 23

Lubricants

Answer 23

During compression of tablets, lubricant act at the interface between the face of the die and the face of the tablet

Insoluble (added to final mix stage but prior to compression) and soluble

Question 24

Glidants

Answer 24

Enhances the flow properties of the powders within the hopper into the tablet press

Essentially, reduces the friction between the powder/granulate and the surface of the hopper

Eg. Talc

Question 25

Absorbents

Answer 25

These materials are used whenever it’s required to include a liquid or semisolid components. E.g. a drug or a flavour Eg. MgO

Question 26

Sweetening, colouring and surface-active agents

Answer 26

Sweetening agent – added to control the taste for bitter drugs and chewable Colouring agent – added to improve the appearance of the tablet or to IDENTIFY the finished product. Surface-active agents – added to enhance the wettability of hydrophobic tablets and aids the rate of disintegration.

Question 27

Adv of wet granulation

Answer 27

Reduce segregation of formulation components Good technique for manufacturing of tablet containing low concentration of drugs Use conventional excipient and most manufacturing plants are built around wet granulation

Question 28

Disadv wet granulation

Answer 28

Several processes are required Solvent required in the process but may cause degradation The drug may be solubilize in the granulation fluids

Question 29

adv dry granulation

Answer 29

Conventional excipients are required No heat or solvent is required This method does not cause alteration in drug morphology

Question 30

Disadv dry granulation

Answer 30

Require the use of special equipment of roller compaction Segregation of the components may occur There are issue regarding powder flow Final tablet formed by dry granulation tend to be softer

Question 31

Adv of direct compression

Answer 31

Few processing and manufacturing steps No need for granulation fluids or solvents, ideal for therapeutic agents that are degradable in presence of solvent Lubrication is performed in the same bowel as powder mixing, reduce transfer loss or contamination Good for small dose tablets

Question 32

DisAdv of direct compression

Answer 32

Specialist equipment is required Segregation may occur but can be reduced by using similar particle sizes Issue with powder flow Can not be used if colourant is required

Question 33

Tablet compression process

Answer 33

Step 1: Filling of the die with the granules/powder - feed by gravity Step 2: Compression of the powder bed - upper punch descent and stress applied Step 3: Tablet ejection - upper punch elevated, shoe of hopper moves across ad push away tablet

Question 34

Types of tablet press

Answer 34

Type 1 : Single-punch presses Type 2 : Rotary tablet presses

Question 35

Technical problems during tabletting

Answer 35

Capping Lamination

Question 36

2 main formulations of tablet coating

Answer 36

Solutions nd emulsion

Question 37

Solution

Answer 37

Coat in coating polymers, coating solvents nd other excipients Increases conc of coating polymer, reducing coating time May increase viscosity of coating matters making it harder to spray

Question 38

Emulsion

Answer 38

More attractive process Polymer dissolved in volatile organic phase Spraying the coating emulsion followed by deposition, spreading and then evaporation of the volatile solvent. This encourages the formation of a coating film

Question 39

Coating of tablet in practise

Answer 39

1. Pan coater 2. Air suspension coater

Question 40

Factors affecting on fluidized air coating

Answer 40

1. Evaporation rate of the solvent 2. Fluidised air volume 3. Specific humidity 4. Coating spray rate and duration