Tablets

Question 1

What are the advantages of tablets?

Answer 1

1. Dose accuracy
2. Stability
3. Pt acceptance
4. Diff techniques to control drug release

Question 2

What are the disadvantages of tablets?

Answer 2

1. Irritation of GI mucosa
   ex: esophageal ulceration
2. Pt’s w/ GERD
3. Elderly (chewable or liquid form)

Question 3

How to prepare tablets w/ molding?

Answer 3

• shaping & hardening of semi-solid mixture of drug & excipients using “tablet mold”
• it’s restricted for small-dose tablet & for small scale production

Question 4

How to prepare tablets w/ compression?

Answer 4

1. Filling
2. Metering
3. Compression
4. Ejection

Question 5

What is granulation?

Answer 5

Poor flow of powders

Need: fluidity & compressibility
1. Spherical shape
2. Normal distribution of particle sizes
3. Homogenous distribution of ingredients
4. Acceptable compression & disintegration properties

Question 6

What are diluents/fillers?

Answer 6

add the necessary bulk to a formulation to prepare tablets of the desired size

for potent drugs

ex: Lactose

Question 7

What are binders?

Answer 7

promote adhesion of the particles to form granules & maintaining the integrity of the final tablet

sugars & polymers freq. added as solutions or slurries to powdered material

ex: Starch, Gelatin, PVP, CMV

Question 8

What are lubricants?

Answer 8

ease of the ejection of the tablet from the die

prevent filling material from sticking to the punches & dies

reduce wear on the tooling

they are applied to coat granules therefore particle size of lubricant is imp. for uniform coating

ex: Magnesium stearate (+SLS)

Question 9

What are disintegrants?

Answer 9

promote tablet breakup after admin to granules then to smaller particles for ready drug avail.

reverse effects of the binder & compression forces

disintegrate may be external or internal

ex: Starch, Cellulose derivatives, Mix of bicarb & organic acid

Question 10

What are glidants?

Answer 10

used to improve flowability in direct compression

function by reducing friction b/t particles or reducing buildup of static charge

enhance the flow of the material into the tablet dies

generally, also have some lubricating property

ex: talc & silicone dioxide

Question 11

What are the 3 tablet manufacturing techniques?

Answer 11

1. Direct compression
2. Dry granulation
3. Wet granulation

Question 12

Compression:

Answer 12

process of pressing material to make it more firm & solid

reduction in the bulk volume by elimination of air

Question 13

Consolidation:

Answer 13

increase in mechanical strength of the mass due to particle/particle interactions (bond formation)

on decompression some of the bonds formed break due to elasticity
- if sufficient bonds remain, a tablet is formed

Question 14

Sticking:

Answer 14

• inadequate lubrication
• granules too dry or wet dirty or scratched die
• worn die

Question 15

Picking:

Answer 15

• inadequate lubrication
• granules under-dried
• scratched or damaged punch face

Question 16

Capping:

Answer 16

• too fast compression speed
• worn tooling
• excessive pressure
• excess fines
• insufficient or ineffective binder
• over-dried granules

Question 17

Content uniformity:

Answer 17

ALL tablets must contain 85-115% of the drug & RSD <6%

Question 18

Weight uniformity:

Answer 18

uncoated tablets, drug > 50 mg & drug > 50% of total weight

Question 19

Disintegration test:

Answer 19

time req. for a tablet to disintegrate in a specified test fluid at a specified temp

if 1 or 2 tablets fail, more 12 tablets are tested. <2 of the 18 tablets fail

Question 20

Dissolution test:

Answer 20

time req. for a tablet to dissolve in a specified test fluid at a specified temp

Question 21

Friability test:

Answer 21

measure of tablet resistance to abrasion

used to assess how a tablet will withstand handing & general wear & tear

Question 22

Tablet breaking force:

Answer 22

force req. to break the tablet at a specific plane (ex: diameter for round tablet)

to determine the ability of a tablet to withstand shocks during handling & shipping

also correlates w/ disintegration & dissolution

Question 23

Applying a coating layer on the tablet core:

Answer 23

1. Controlling drug release
2. Taste or odour masking
3. Physical & chemical protection
4. Protecting the drug from the gastric environment

Question 24

What are the various techniques for tablet coating:

Answer 24

1. Sugar coating
2. Film coating
3. Enteric coating

Question 25

Sugar-coating:

Answer 25

• water soluble coating quickly dissolves after swallowing
• protects the drug from the environment
• provides a barrier to objectionable taste or odour
• permits imprinting of identifying manufacturer’s info

Question 26

What is the downside of sugar-coating?

Answer 26

• may add 50% to the weight of the uncoated tablet
• increase in size, weight, & shipping costs
• the time & expertise req. in the coating process (sealing, subcoating, syruping, finishing & polishing)

Question 27

What is Film coating?

Answer 27

using one or more film forming polymers capable of forming a skin-like film on the surface of the tablet

Question 28

What are the advantages of film coating over sugar coating?

Answer 28

• more durable, less bulky
• usually film represents less than 5% of the finished tablet weight
• film coating may be enteric or non-enteric in nature
• less time-consuming to apply

Question 29

What is the criteria of a film forming material?

Answer 29

• soluble in solvent suitable for process
• soluble in GI fluids
• forms a strong continuous film which is smooth & elegant
• stable to heat, light, air, moisture, & compatible w/ the drug in the product
• have no appreciable taste, odour, or colour
• able to support pigment or coating additives
• non-toxic
• crack resistant (usually by inclusion of additive)

Question 30

What is the film coating formula?

Answer 30

• Non-enteric coating material: usually are cellulose
• Enteric material: usually phthalate esters of cellulose
• it’s common to use a mixture of materials to give a film w/ the desired properties
• a plasticizer is included to prevent the film from chipping
• mixture of solvents to control evaporation
• colouring agents