Manufacturing final

Question 2

What is the overall tablet manufacturing process?

Answer 2

Comminution → Mixing → Granulation (or direct compression) → Compaction → Coating.

Question 3

What materials can tablets be produced from?

Answer 3

Granules or primary powder particles (direct compression).

Question 4

What is powder compression?

Answer 4

Reduction in powder volume when pressure is applied in the die.

Question 5

What is powder compaction?

Answer 5

Formation of a strong tablet that remains intact after pressure is removed.

Question 6

Why can a powder compress well but still form a weak tablet?

Answer 6

It may have poor compactability.

Question 7

What is compressibility?

Answer 7

Ability of a powder to decrease in volume under pressure.

Question 8

What is compactability?

Answer 8

Ability of a powder to form a coherent tablet after compression.

Question 9

What are the stages of a single-punch tablet press cycle?

Answer 9

Die filling → compression → ejection.

Question 10

Stage 1 of compression: particle rearrangement — what happens?

Answer 10

Particles reposition and fill void spaces.

Question 11

Stage 2: deformation — what occurs?

Answer 11

Particles flatten under pressure.

Question 12

Difference between plastic and elastic deformation?

Answer 12

Plastic = permanent change (good bonding); Elastic = spring-back (bad bonding).

Question 13

What problem can elastic recovery cause?

Answer 13

Tablet cracking or capping.

Question 14

Stage 3: fragmentation — what happens?

Answer 14

Brittle particles break creating new surfaces for bonding.

Question 15

Stage 4: densification — what occurs?

Answer 15

Bond formation increases tablet strength and decreases porosity.

Question 16

Why does air exist in powders before compression?

Answer 16

Air occupies spaces between particles.

Question 17

What happens if compression is too fast?

Answer 17

Air becomes trapped.

Question 18

What defect does trapped air cause?

Answer 18

Capping after ejection.

Question 19

How do industrial presses reduce air entrapment?

Answer 19

Pre-compression step allows air escape.

Question 20

Why does fragmentation improve tablets?

Answer 20

Increases surface area and van der Waals bonding.

Question 21

Which materials generally tablet better — brittle or elastic?

Answer 21

Brittle (e.g., lactose).

Question 22

What compaction processes occur in granules?

Answer 22

Densification, attrition, and deformation of primary particles.

Question 23

What types of bonding form tablet strength?

Answer 23

Solid bridges, liquid/binder bridges, van der Waals forces, electrostatic forces, mechanical interlocking.

Question 24

Role of glidants (e.g., colloidal silica)?

Answer 24

Improve flow and die filling.

Question 25

Role of lubricants/anti-adherents (e.g., magnesium stearate)?

Answer 25

Reduce friction and prevent sticking during ejection.

Question 26

Why can excess lubricant weaken tablets?

Answer 26

Coats particles and prevents bonding; also slows dissolution.

Question 27

What is capping?

Answer 27

Top of tablet separates from the body.

Question 28

Causes of capping?

Answer 28

Air entrapment, elastic recovery, fines accumulation, poor mixing, low binder/moisture.

Question 29

What is lamination?

Answer 29

Tablet splits into layers.

Question 30

Causes of lamination?

Answer 30

Over-compression and poor cohesion.

Question 31

What is tablet coating?

Answer 31

Application of a dry outer layer onto a tablet.

Question 32

Purposes of tablet coating?

Answer 32

Protection (moisture/light), safety, taste masking, appearance, identification, modified release.

Question 33

What is film coating?

Answer 33

Thin polymer coating layer.

Question 34

Film coating composition?

Answer 34

Polymer (HPMC/PVA), plasticiser (PEG), solvent (water), colourant.

Question 35

Types of film coating release?

Answer 35

Immediate, enteric, extended release.

Question 36

What is enteric coating?

Answer 36

Dissolves at pH >5–6 (intestine).

Question 37

Characteristics of sugar coating?

Answer 37

Thick, multi-step, increases tablet weight by ~50–100%.

Question 38

What is compression coating used for?

Answer 38

Separate incompatible drugs and modified release.

Question 39

What equipment is used for tablet coating?

Answer 39

Coating pan and fluidised bed coater.

Question 40

Common film coating defects?

Answer 40

Peeling, orange peel effect, mottling, and bridging.

Question 41

Requirements for direct compression tablets?

Answer 41

Good flow, compressibility, and compactability.

Question 42

What improves tablet strength during compaction?

Answer 42

Fragmentation.

Question 43

What causes capping?

Answer 43

Elastic recovery or air entrapment.

Question 44

How do lubricants affect tablets?

Answer 44

Aid ejection but excess weakens tablets and slows dissolution.

Question 45

How can coatings affect drug action?

Answer 45

Control site of drug release in the GI tract.

Question 46

What key principle summarises tablet manufacturing?

Answer 46

Tablet quality begins with particle behaviour.

Question 47

What happens first when compression force is applied to a powder bed?

Answer 47

Particles rearrange and slide into void spaces, reducing bulk volume.

Question 48

Why does particle rearrangement not yet create a strong tablet?

Answer 48

No true bonding occurs yet; particles are only packed closer together.

Question 49

What is densification during tablet compaction?

Answer 49

Reduction in porosity as particles pack closer together under pressure.

Question 50

What happens during plastic deformation of particles?

Answer 50

Particles permanently flatten and increase contact area with neighbours.

Question 51

Why does plastic deformation improve tablet strength?

Answer 51

Larger contact area allows stronger intermolecular bonding.

Question 52

What happens during elastic deformation?

Answer 52

Particles temporarily deform but return to original shape after pressure release.

Question 53

Why is elastic deformation undesirable in tablets?

Answer 53

Elastic recovery after ejection weakens bonds and can cause capping.

Question 54

What occurs during fragmentation in brittle materials?

Answer 54

Particles fracture into smaller pieces creating fresh clean surfaces.

Question 55

Why do newly formed surfaces improve tablet bonding?

Answer 55

Clean surfaces allow stronger van der Waals and intermolecular bonding.

Question 56

Why do brittle excipients (e.g., lactose) tablet well?

Answer 56

They fragment easily and form many bonding surfaces.

Question 57

When does true tablet strength develop during compression?

Answer 57

During bond formation at maximum compression force.

Question 58

What are solid bridges in tablets?

Answer 58

Permanent bonds formed after particles fuse or crystallise at contact points.

Question 59

What are binder (liquid) bridges?

Answer 59

Binder solution dries and solidifies, gluing particles together.

Question 60

How do van der Waals forces contribute to tablet strength?

Answer 60

Weak intermolecular attractions form when particles are very close together.

Question 61

What is mechanical interlocking in compaction?

Answer 61

Irregular particles physically hook into each other, strengthening the tablet.

Question 62

What happens immediately after pressure is released?

Answer 62

Elastic recovery causes slight tablet expansion.

Question 63

Why can excessive elastic recovery cause defects?

Answer 63

Expansion breaks newly formed bonds leading to capping or lamination.