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Flashcards in Solid dosage forms Deck (74):
1

What are some of the disadvantages of tablets?

manufacture requires a series of unit processes - product loss at each stage
drug absorption is dependent on gastric emptying rate
compression difficulties due to powder physical properties

2

What is the definition of excipient?

An inert substance that is used as a diluent or vehicle for preparing a drug product

3

For high dose tablets, the active ingredient is < 5% of the tablet weight. True or false?

False >50% of tablet weight

4

For low dose tablets, what % of tablet weight dose the active ingredient make?

< 5%

5

The total tablet weight should be less than ___mg to be viable to swallow

800mg

6

High dose tablets require a filler. True or false?

False - low dose <5mg tablets do

7

The filler used in tablets should be hygroscopic. True or false?

False - non-hygroscopic as you don't want it to absorb water as they make bulk of tablet

8

Why is a filler needed in a low dose tablet?

For ease of manufacture and handling

9

What is the need for a disintegrant in a tablet?

To ensure the tablet breaks up into smaller fragments

10

What is the role of a binder in a tablet?

Added to ensure that the tablet can be formed with the required mechanical strength

11

What is the role of a glidant in a tablet?

To improve flowability of the powder - either for direct compaction or for granulation

12

Name a glidant

talc

13

Name a binder

PVP

14

Name a filler

Sucrose

15

Name a disintegrant

Starch

16

What is the role of a lubricant in a tablet?

To ensure that tablet formation and ejection can occur with low friction between the tablet and the die

17

Name a lubricant

Magnesium stearate

18

Why would you want to minimise the amount of lubricant in a tablet, although it helps with tablet formation?

Because they are usually lipophilic and so will hinder the dissolution and disintegration of the tablet if too much is used

19

What is the role of an antiadherent in tablet?

To reduce the adhesion between the powder and the punches which could otherwise lead to uneven tablet surface

20

What is tensile strength used to measure?

adhesive/cohesive properties

21

What is meant by tensile strength?

How easy it is to introduce a breakage in the tablet

22

What does a high angle of repose indicate?

High cohesive forces

23

When the angle of inclination is greater than the frictional force, does the powder slide or stop sliding?

Slide

24

How can powder flow be improved?

Increase the particle size of powder e.g. by granulation
Alter surface forces - controlled temp, humidity etc.
Formulation additives e.g. glidants, lubricants
Change process conditions - vibration assisted hoppers, force feeders

25

What is granulation?

Primary powder particles are made to adhere to form larger multi-particle entities called granules

26

Why use granulation?

Granules flow better than powder
Prevent segregation of ingredients
Improve compaction
Ease of transport as they are less dense than powder and so occupy less vol/unit weight

27

What is the mechanism of granulation? (3 steps)

Nucleation
Transition (nuclei growth)
Granule growth

28

Wet granulation is suitable for temperature and moisture sensitive material. True or false?

False - dry granulation is

29

What are some advantages of dry granulation?

Economical - less energy costs
Low equipment costs
Easy to scale up

30

Bulk density affects die filling. True or false?

True

31

Uniformity of content test is recommended for all pharmaceutical preparations. True or false?

False - compulsory

32

How many tablets should be tested for uniformity of content?

More than 5 - to be representative

33

What are the accepted % limit for API in uniformity of content test?

90-110%

34

There is a direct correlation between uniformity of content and tablet weight. True or false?

True

35

In tablet weight testing, no more than two tablets should have a mass difference of more than 20%. True or false?

False - 10%

36

What happens to a tablet that is ingested but doesn't disintegrate in the body?

It gets excreted

37

How many tablets need to fail the disintegration test for it to be repeated on a second full batch?

2 tablets

38

What is the definition of dissolution?

The transfer of molecules or ions from the solid state into solution

39

What are the two methods of conducting dissolution tests?

Stirred vessel method
Continuous flow method

40

Dissolution is independent of temperature. True or false?

False - dependent on temperature

41

If a reaction is exothermic, will dissolution be favoured by an increase in temperature?

No

42

What are the two possible apparatus for dissolution in the stirred vessel method?

Basket
Paddle

43

Which dissolution method is a better mimic of GIT conditions?

Continuous flow

44

The mechanical strength of a tablet it associated with resistance of the solid specimen to what two thing?

Fracturing and attrition

45

What are friability tests used to mimic?

Forces that are present in production, storage and administration

46

In the friability test you are looking for a less than 5% weight loss in the tablet. True or false?

False - less than 1%

47

In a friability test, how many tablets are tested?

20 tablets in revolving cycle

48

When testing the tablets resistance to crushing, if the tablet splits in two, does it pass the test?

Yes

49

What are gastro-retentive tablets designed for?

To be retained in the upper GIT

50

Mucoadhesive tablets are designed to stick for a long period of time. True or false?

True

51

What are the 3 types of coating?

Film
Sugar
Compression

52

What is titanium dioxide used as in coating?

A colourant

53

Are tablets more evenly coated if a horizontal spray is used or a tilted spray is used?

Tilted

54

What are some problems that are associated with coating?

Erosion, peeling and breakage
Poor mechanical strength
Uneven coat
Tablet peeling

55

Sugar coating involves successive applications of ______ solution

sucrose

56

What are the characteristics of tablets that are coated with a sugar coating?

Immediate release of drug - as sugar is very soluble in water
Masked taste of tablet

57

Main reason of using a sugar coating is for masking taste rather than functionality. True or false?

True - would still need a film coat e.g. enteric if you want functionality

58

A sugar coat doesn't add much weight to the total tablet weight. True or false?

False - adds a lot of weight 30-50%

59

Sugar coating a tablet is a quick process. True or false?

False - takes over 8 hours

60

What are the 6 steps involved in sugar coating process?

Sealing
Subcoating
Smoothing
Colouring
Polishing
Printing

61

Compression coating allows for 2 drugs to be present in one tablet. True or false?

True - one drug in the coating and one in the core

62

Soft gelatin capsules cannot be filled with liquid. True or false?

False - can be filled with liquid - helps to increase solubility or permeability of drug across cell membrane

63

Soft gel capsules are not suitable for potent drugs. True or false?

False

64

Why is there no risk of leakage in a soft gel capsule?

Because it is one piece that is sealed

65

Why is it harder to have a liquid in a hard capsule?

Because there is risk of leakage - the capsule is made of two pieces

66

Hard capsules are all one size. True or false?

False - they can be different sizes to accommodate for different volumes within the capsule

67

Hard capsules are filled with liquid. True or false?

False - powder, or more normally pellets

68

The hard capsule shell doesn't give any controlled release properties. True or false?

True - if you want controlled release, this has to be done at the granulation stage of the process

69

Hydrolysis only occurs in the presence of water. True or false?

False - water, acid or base

70

Most ibuprofen is supplied as a racemic mixture. Unusually, this drug is converted to the R-form in the body. True or false?

False - converted to the S form

71

What does a maillard reaction occur between?

Lactose and an amide containing drug, resulting in a glycosylamine.

72

How can a maillard reaction be prevented?

By using an alternative diluent to lactose such as mannitol

73

Replacing an aqueous solvent with a non-aqueous solvent will maximise the stability of the drug. Why?

Because it will be less prone to hydrolysis

74

Magnesium stearate only acts as a lubricant. True or false?

False - lubricant, glidant, anit-adherent