Excipients for IR Tablets

Question 1

What are the different immediate release tablets?

Answer 1

Disintegrating tablets
Chewable tablets

Question 2

How are tablets produced?

Answer 2

Powder compcation

Question 3

How are immediate release tablets defined?

Answer 3

75% of drug released before 45mins
BP

Question 4

What is filler used for?

Answer 4

Increase tablet size
>50mg

Question 5

What are common fillers?

Answer 5

Starch, lactose + microcrystalline cellulose

Question 6

What is binder used for?

Answer 6

Adhesive to make tablets stick together
Increases compactability

Question 7

What if too much binder?

Answer 7

Tablet too hard
= hinder disintegration + dissolution

Question 8

What are common binders?

Answer 8

Lactose, microcrystalline cellulose + pregelantised starch

Question 9

What is lubricant used for?

Answer 9

Reduce friction between tablet + die

Question 10

What is anti-adherent used for?

Answer 10

Prevent powder adhesion to punches

Question 11

What is glidant used for?

Answer 11

Reduce powder cohesion
Improve powder flowability
Improve mixing + content uniformity

Question 12

What are common lubricants, anti-adherents + glidants?

Answer 12

Magnesium stearate, talc + colloidal silica

Question 13

How does boundary lubrication work?

Answer 13

Coat particle surface
= slide past each other easily
(Sit at boundary between interface)
= reduce friction

Question 14

What is the problem with lubricants?

Answer 14

Hydrophobic = excessive amounts impair wetting + dissolution

Question 15

What does disintegrant do?

Answer 15

Break up tablet into smaller particles

Question 16

Why does disintegrant increase specific SA?

Answer 16

Expose internal surfaces

Question 17

What is superdisintegrant?

Answer 17

High performing
More rapid

Question 18

What is effervescent disintegrant?

Answer 18

Fizzes in contact with H2O

Question 19

Why do we coat excipients?

Answer 19

Mask taste
Improve ease of swallowing
Reduce friability

Question 20

Why is friability bad?

Answer 20

Lose powder content during transport
= correct dose not given

Question 21

What is colouring added for?

Answer 21

Aid tablet identification

Question 22

What is flavouring added for?

Answer 22

Enhance taste

Question 23

When is flavouring added?

Answer 23

For tablets that are chewable + stay in mouth for a long time

Question 24

Can the same excipient exert different amounts?

Answer 24

YES when used at different amounts

Question 25

Can things like binder + disintegrant be used in same tablet even though they exert opposite functions?

Answer 25

YES = they do different things at different times eg. disintegrant only works when in contact with H2O

Question 26

Describe disintegration

Answer 26

1st step in tablet dissolution Accelerated by disintegrants

Question 27

When is disintegration increased?

Answer 27

Higher dissolution rate

Question 28

Describe mechanism of swelling for disintegration

Answer 28

H2O uptake = forces tablet apart Degree of swelling depends on particle size

Question 29

Why are their cross-links in polymers?

Answer 29

Make sure polymers swell BUT don't break apart when uptake of H2O

Question 30

Describe mechanism of wicking for disintegration

Answer 30

Create hydrophilic conduits in tablet = H2O drawn into tablet

Question 31

Describe mechanism of strain recovery for disintegration

Answer 31

Particles undergo elastic deformation in tablet formation + interlock = H2O relaxes particles = return to spherical shape

Question 32

Describe mechanism of heat of interaction for disintegration

Answer 32

Heat released when particles interact with H2O = exothermic = air trapped in tablet absorbs energy + expands

Question 33

Describe mechanism of interruption of bonding forces for disintegration

Answer 33

Bonds weaken in aq environment = dissolution

Question 34

Describe mechanism of repulsion for disintegration

Answer 34

H2O uptake = electrostatic repulsion between particles = same charged particles repel

Question 35

What is an example of superdisintegrant?

Answer 35

Sodium starch glycolate = cross-linked starch

Question 36

Describe how effervescent disintegrant work?

Answer 36

Carbonate + bicarbonate break down to CO2 + H2O in acidic conditions