Oral solid dosage forms

Question 1

What are tablets?

Answer 1

solid preparations containing a single dose of more than one drug

Question 2

What are the different types of tablet?

Answer 2

caplet, effervescent, dispersible, buccal, sublingual, chewable, vaginal/rectal tablets, MR, coated, lozenges

Question 3

Why would you coat a tablet?

Answer 3

• to protect the drug
• to mask the taste
• for identification
• easier to swallow
• to change the release properties

Question 4

What are the different types of coating?

Answer 4

film (polymers) or sugar coated (SC)

Question 5

What are capsules?

Answer 5

One or more drugs enclosed in a gelatine shell

Question 6

What is the difference between hard a soft gelatine?

Answer 6

Hard gelatine has a 2 piece outer shell and can be filled with powder, granules or pellets whereas soft gelatine has a one piece gelatine shell and it can be opened for external use

Question 7

What is the difference between powders and granules?

Answer 7

powders are finely divided solids whereas granules are powders that have been aggregated together to form larger particles. Granules are for internal use only.

Question 8

What are the excipients needed in oral solid forms?

Answer 8

• dilutents/fillers to add bulk (lactose, cellulose)
• binders to make the granules (gelatine, cellulose)
• disintegrants to break the tablet up (starch)
• lubricants to improve flow properties (magnesium stearate)
• colourants (E-number)

Question 9

How do effervescent tablets work and what are the excipients needed for this?

Answer 9

A reaction occurs between a carbonate and weak acid to produce CO2 which breaks the tablet up
-an example of a carbonate and weak acid is sodium carbonate and citric acid

Question 10

What specific excipients are needed in chewable tablets?

Answer 10

sweeteners (to aid solubility and for taste e.g. mannitol) and flavourings

Question 11

What are the 3 different types of modified release forms?

Answer 11

1. delayed release
2. enteric coating (pH dependent)
3. extended release

Question 12

How does enteric coating work?

Answer 12

It prevents release of drug in the stomach to either protect the drug or protect the stomach

Question 13

What are the different methods used for MR?

Answer 13

• Matrix system: made of polymers and can be split
• Reservoir/membrane system: this coating creates a semi-permeable barrier, it’s made from polymers and plasticisers and can NOT be split

Question 14

What is a desiccant and what can it help maintain?

Answer 14

A desiccant is a drying substance and is used for stability

Question 15

What are the advantages of tablets and capsules?

Answer 15

• very stable
• convenient
• easy to make and at a low cost
• taste can be masked
• release can be modified

Question 16

What are the disadvantages of tablets and capsules?

Answer 16

• slow onset of action
• 1st pass metabolism
• systemic action and side effects
• gelatin issues
• difficulty swallowing

Question 17

What are the advantages of powders and granules?

Answer 17

• very stable and can be reconstituted to liquids
• accurate dosing from sachets
• faster onset of action
• good for large doses

Question 18

What are the disadvantages of powders and granules?

Answer 18

• 1st pass metabolism
• systemic action and side effects
• difficult to mask taste