25 Tablet techonology

Question 1

Define ‘tablet’

Answer 1

A compressed solid dosage form that contains drugs, with or without excipients.

Question 2

What are advantages of tablets? (8)

Answer 2

• precise dose
• easy use
• convenient to carry
• large scale manufacturing
• low cost of excipients
• taste making
• complex design possible
• high stability

Question 3

What are disadvantages of tablets? (5)

Answer 3

• difficult to swallow
• limited dose flexibility
• difficult to compress some drugs
• special packaging required
• bioavailability issues

Question 4

When are ideal flow and compression properties observed, and why is this important?

Answer 4

Ideal properties are when particles are 0.2-0.5mm diammeter.
This is important for when tablets are made - particles need to have good flowability and compressibility to go through the feed tube and be compressed.

Question 5

What is direct compression and a notable property?

Answer 5

blend or raw materials (active ingredients and excipients).

Direct compressed tablets break down more easily.

Question 6

What are advantages and disadvantages of direct compression?

Answer 6

adv:
- fast and cost effective
- minimal additives required
- powders do not go through pre-processing which is good for heat and moisture sensitive drugs.
disadv:
- powders need good flowability and compressibility (most drugs do not possess this)
- powder size range is generally varaible so there is not a uniform blend.

Question 7

What is granulation?

Answer 7

Formation of granules 0.2-0.5mm in diammeter prior to compression to be in the ideal flow range.

Question 8

What are advantages and disadvantages of granulation?

Answer 8

Adv:
- idea compression and flow properties
- narrow size distribution will ensure uniform material enters the tablet die (more homogenous composition)
- can use higher quantity of active drug as active drug granules are easier to compress.
Disadv:
- stability (moisture and heating required while pre-processing)
- cost
- cross contamination

Question 9

What is the most popular manufacturing method for tablets? why?

Answer 9

Wet granulation

• homogenous powder mixture
• can use high drug concentration
• strongest tablet

Question 10

Excipients used to make a formulation…. (5). Give an example for each point.

Answer 10

• easy to produce in bulk (binders/adhesives)
• non-irritant (diluents)
• behaving in a desired fashion (disintergrants)
• aesthetic and palatable (colouring)
• stable (coatings)

Question 11

What is a diluent? what does it do? give an example.

Answer 11

Diluents are fillers used when a drug dosage itself is too small to produce the bulk of a tablet. Also used to reduce irritation of drug.
Must be cheap, non-toxic, non-reactive, aesthetic and ideally compressible.
Example: lactose

Question 12

What is a binder/adhesive? what does it do? give an example

Answer 12

Ensures tablets stay intact.
Helps powder particles/granules adhere to one another within the formulation. Usefule for both direct compressed and granulated tablets.
Example: acacia

Question 13

What is a glidant? what does it do? give an example.

Answer 13

Prevents friction between particles to improves powder/granule flow.
example: cornstarch

Question 14

What is a lubricant? what does it do? give an example.

Answer 14

Lubricants prevent tablet materials from adhering to surfaces of dies/punches during manufacturing and improves powder/granule flow.
example: stearic acid

Question 15

What is a disintegrant? what does it do? give an example

Answer 15

disintergrants ensure that tablets break down once in the body or in contact with water.
Example: starch + derivatives

Question 16

Why are tablet coatings used?

Answer 16

• Typically added after compression
• Protects tablet contents, or serve functional role e.g. Enteric coating, osmotic pump exterior
• Easier to swallow and aesthetically favourable.

Question 17

why are colouring/flavouring/sweetening agents used?

Answer 17

• colouring agents used for appearance and identification
• Flavouring/sweetening agents used to mask taste of certain drugs
• -> especially useful in tablets that are dissolved before swallowing or act in oral cavity.

Question 18

What are the different types of orally ingested tablets? (7)

Answer 18

• standard compressed
• multiple compressed
• repeat action/ sustained release
• delayed release
• sugar/film coated
• chewable
• oral disintergrating

Question 19

what are different types of tablets used in the oral cavity? (4)

Answer 19

• buccal
• Sublingual
• Troches/lozenges
• Dental cone

Question 20

What are different types of tablet administered non-orally? (2)

Answer 20

• vaginal

- implantation

Question 21

What are different types of tablets used to prepare solutions? (4)

Answer 21

• effervescent
• dispersing
• hypodermic (injectable)
• triturates (injectable)

Question 22

what is a single vs multiple compression tablet?

Answer 22

Single compression tablets are straightforward and fast but is often unable to combine incompatible actives.
Compression of actives in different layers then combining this through multiple compressions allows physically or chemically incompatible drugs to exist in the same drug.

Question 23

define repeat action, sustained release and delayed release

Answer 23

repeat action: external layer releases immediately and internal layer releases drug slowly.
Sustained release: specialised excipients can be used to slow down drug release.
delayed release: enteric coatings to ensure drug is not released until it reaches a specific part of the GI tract.

Question 24

Describe oromucosal delivery.

Answer 24

two types; buccal (inside cheeks) and sublingual (under the tongue). Can act locally or have systemic effects.
Muscoadhesion is important in local action. This can be acheived by incorportation of polymer prolonging contact of tablet with mucous membrane.

Question 25

Describe intravaginal delivery

Answer 25

commonly used to treat local diseases affecting the female reproductive system. Mucoadhesion is important for local action and can be acheived by incorporation of polymers to prolong contact time with the mucous membrane.

Question 26

Describe chewable delivery.

Answer 26

Useful for paediatic delivery as children have difficulty swallowing tablets. Also allows large doses to be administered.
Acts rapidly where chewing increases surface area when working on the stomach.
Flavouring shuld be considered for palatibility.

Question 27

Describe lozenges

Answer 27

Typically for slow release in local delivery systems to the oromucosa or slightly downstream. May be used for systemic absorption e.g. nicotine lozenges.
Predominantly sugar based.

Question 28

Describe dispersible and oral disintegrating delivery forms

Answer 28

Dispersible tablets rapidly break down in a glass of water.
Disintegrating tablets break down rapidly in saliva.
Able to do so via:
- structure (porous and high SA); direct compression is cheapest way to achieve this. Freeze drying may also be employed.
- inclusion of super-disintegrants; excipients that rapidly absorb water or dissolve in aqueous media.