Routes of Administration: Oral (capsules)

Question 1

State the advantages of capsules.

Answer 1

• Easy to swallow (smooth, slippery)
• Easy to handle and carry
• Easy to identify
• Mask taste and smells of drugs using odourless and tasteless shell
• Minimal excipient needed
• Minimal pressure is required to compact the materials
• High drug loading is possible as compared to tablets

Question 2

State the disadvantages of capsules

Answer 2

• Not suitable for highly soluble substances - can cause sudden release in the stomach resulting in irritation
• Not suitable for highly deliquescent materials - may dry the capsule shell causing brittleness
• Product cost is mostly more than oral tablets

Question 3

Describe how gelatine is prepared.

Answer 3

• By hydrolysis of collagen from connective tissues
• Commonly made from calf bones and pig skin

Question 4

What are the properties of gelatine?

Answer 4

• Non-toxic and non-irritant
• Soluble in biological fluids at body temperature
• Good film forming properties - produces strong flexible film
• Solutions of high concentration
• Changes from solution to gel at temperatures just above room temp; enables gelatine films to be prepared easily

Question 5

What are the problems with gelatine?

Answer 5

• Allergy
• Not suitable for vegetarians and vegans
• Not suitable for certain ethnic groups or religious beliefs

Question 6

How must hard capsules be stored?

Answer 6

• Empty gelatine capsules are designed to have a moisture content between 13-16%
• Store at controlled temperature and humidity

Question 7

What are the requirements of the filling in hard capsules?

Answer 7

• Be free from large amounts of moisture
• Not react with the shell
• Not leak out
• Have good powder flow
• Not be adhesive
• Be capable of being filled uniformly

Question 8

State the different excipients used in powder filled capsules.

Answer 8

• Diluents - bulk forming properties
• Lubricants - reduce powder to metal adhesion
• Glidants - reduce powder cohesion
• Wetting agents - improve water penetration
• Stabilisers - improve product stability
• Disintegrants - produce disruption of the powder mass

Question 9

What do soft capsules consist of?

Answer 9

• Consists of a liquid or semisolid matrix sealed inside a one-piece flexible solid-phase gelatine shell

Question 10

What are the advantages of soft capsules?

Answer 10

• Improved drug absorption - drug is already in solution
• Convenience, ease of use, no unpleasant taste
• Enhanced safety: no airborne powders during manufacture
• Dose uniformity and precision; drugs are in solution during manufacturing which provides better homogeneity and flow than powder
• Product stability: drug is protected by the soft gel shell and liquid vehicles against oxidation, moisture

Question 11

What is the composition of soft gel shell?

Answer 11

• Gelatin
• Plasticisers
• Water
• Others as needed e.g. flavour, dye

Question 12

What are the types of soft gel fill matrices?

Answer 12

• lipophilic liquids e.g. triglyceride oils
• Hydrophilic liquids e.g. polyethylene glycol
• Self-emulsifying systems