Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pharmaceutics Year 2 > Section 5 - Tablets > Flashcards

Section 5 - Tablets Flashcards

1
Q

What is a tablet?

A

A unit dose form of medication containing one or more drugs that are compressed as granules or powder to a definite shape

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Can tablets have excipients added?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the popularity of tablets due to?

A

1) Dosing accuracy
2) Stability
3) Patient acceptance
4) Diversity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Drugs in solid state are generally ____ chemically stable

A

More

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Do drugs in the solid state have a longer or shorter half-life?

A

Longer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Are all tablets swallowed?

A

No, some are sublingual, implant, or chewable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are some disadvantages to tablets?

A
  • Solid dose form may cause local irritation to GI mucosa

- May have bioavailability problems since dissolution must occur before drug is available for absorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are some attributes that a tablet must have?

A
  • Able to withstand rigors of mechanical treatment during production, packaging, shipping, and dispensing
  • Free of defects (cracks, chips, discolouration)
  • Reasonable chemical and physical stability
  • Contain the proper amount of medication and release it in a predictable and reproducible manner
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the 2 essential characteristics that materials intended for compression into a tablet must have?

A

Fluidity and compressibility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Why is fluidity necessary for granulation?

A

Necessary for the transport of the material through a hopper into a feeder frame or die cavity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is compressibility?

A

The property of forming a stable compact when pressure is applied

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Do powders generally flow freely?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What can poor flow lead to?

A

Variable fill of the cavity and consequent variation in tablet weight, content, and hardness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Are granules free-flowing?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Do granules have good compression properties?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Almost all problems relating to tablet production are caused by ____

A

A problem w/ the granules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the most important step in tablet production?

A

Granulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are attributes that good granulation should have?

A
  • Approach spherical shape
  • Present a narrow range of particle sizes
  • Have homogenous distribution of all materials
  • Have acceptable compression properties
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Why should granules approach spherical shape?

A

To minimize inter-particle friction and static charge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Why should granules present a narrow range of particle sizes?

A

It provides uniform fill and bridges between particles when compressed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are acceptable compression properties?

A

Hard enough to remain intact, yet be able to disintegrate when taken

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Are excipients used in granulation? Why?

A
  • Yes

- To confer appropriate properties to granules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the benefits of excipients to granulation?

A
  • Some aid in granule formation and flow
  • Some aid in compression
  • Some aid in disintegration and dissolution
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What must an excipient do or not do when added to a granule?

A
  • Not compromise product stability

- Must conform to pharmacopeial standards

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Why are diluents used with potent drugs?

A

B/c drug may have a dose in the microgram range and a diluent is needed to give the product adequate bulk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are some examples of diluents (fillers)?

A
  • Lactose
  • Sucrose
  • Mannitol
  • Sorbitol
  • Calcium sulfate
  • Calcium phosphates
  • Starch
  • Microcrystalline cellulose
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the choice of filler based on?

A
  • Desired specifications of finished product

- Stability/compatibility aspects of API

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are some properties of lactose crystals that are beneficial to compressibility?

A
  • Crystals tend to be plastic

- Tend to deform under pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Is lactose hydroscopic?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is a disadvantage to lactose as a diluent?

A

Prone to “browning” w/ some drugs, and may lose some compressibility characteristics w/ some drugs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is sucrose often used for as a diluent?

A

To impart hardness to tablets, but used in small amounts b/c somewhat hydroscopic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What tends to happen w/ tablets that contain sucrose?

A

Harden w/ time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Is sucrose prone to browning?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Is mannitol inert?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Is mannitol hydroscopic?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

When is mannitol used as a diluent?

A

In chewable tablets b/c it feels good in the mouth (cool, smooth, slightly sweet)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Calcium sulfate has ___ solubility

A

Low

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Is calcium sulfate hydroscopic?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Calcium sulfate has ____ absorption of oils

A

Good

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Does calcium sulfate harden with time?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What is microcrystalline cellulose?

A

Insoluble, inert free-flowing filler which can also function as binder and disintegrant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

When is microcrystalline cellulose mostly used?

A

In direct compression

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Microcrystalline must be added ___ to granules to improve binding

A

Dry

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What do binders do?

A

Hold powders together, causing the to form granules, by adding cohesive forces to diluent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Are binders used often?

A

No, must be used w/ care since tablets must disintegrate at some point

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What are common binders used in wet granulations?

A
  • Starch
  • Pregelatinized starch
  • Gelatin
  • Polyvinylpyrrolidone
  • Methycellulose
  • Ethylcellulose
  • Polyvinyl alcohols
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What is the most common binder?

A

Starch (corn)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Starch is a good carrier for ____

A

Dyes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Is starch charged?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Is starch reactive?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Are additional excipients required w/ starch and why?

A

Yes b/c may give soft granules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

____ is a stronger binder than starch

A

Gelatin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What are disadvantages to gelatin use as a binder?

A
  • Tablets w/ gelatin harden over time
  • Granules are quite hard, and gelatin must be added while hot, which leads to some problems (thermosensitivity and dissolution)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

The use of gelatin has been replaced by _____

A

Synthetic polymers

55
Q

What are 2 examples of natural gums?

A

Acacia and tragacanth

56
Q

What is a problem w/ natural gums?

A

Bacterial contaminants

57
Q

Is polyvinylpyrrolidone hydroscopic and what does this mean?

A
  • Slightly

- Tablets don’t harden w/ time

58
Q

In which solvents can polyvinylpyrrolidone be used?

A

Alcoholic and hydro-alcoholic solvents

59
Q

Why are cellulose derivatives used as binders?

A

Good binding properties and very versatile

60
Q

What are the most common cellulose derivatives used as binders?

A
  • Methylcellulose
  • Carboxymethylcellulose
  • Ethylcellulose
  • Hydroxypropylmethylcellulose
61
Q

Why are lubricants used?

A
  • To ease ejection of the tablet from the die
  • To prevent sticking to the faces of the punches
  • To reduce wear on tooling
62
Q

Where are lubricants applied?

A

To coat the granules, therefore particle size of lubricant is important since we want uniform coating

63
Q

What is the most common lubricant used?

A

Magnesium stearate

64
Q

What is a disadvantage to magnesium stearate?

A

Slightly alkaline, may cause problems and tend to waterproof granules which may affect disintegration or dissolution properties of tablets

65
Q

What are disintegrants?

A

Substances applied to granulation to cause tablet to break apart in aqueous environment

66
Q

What is the ideal function of disintegrants?

A

Should cause the tablet to disrupt into the granules from which it was compressed, and then into the powder particles from which the granules were prepared

67
Q

___ reverse the effect of a binder

A

Disintegrants

68
Q

When are disintegrants external?

A

When added to the formed granules just prior to compressino

69
Q

When are disintegrants internal?

A

When it is a component in the granulation mixture

70
Q

How do disintegrants work?

A

By swelling or reacting w/ water to cause disruptive forces

71
Q

Colorants are usually added to ____

A

Tablet formulation

72
Q

Why are colorants used?

A

To increase elegance or for identification

73
Q

Why are pastel shades often used as colorants?

A

Least likely to slow mottling

74
Q

Why are colorants frequently used as lakes?

A

Less likely to bleed and better uniformity

75
Q

What are the steps in wet granulation?

A

1) Milling of drug and excipients
2) Mixing of milled powders
3) Preparation of binder and wet mass
4) Screening of wet mass
5) Drying of granules
6) Screening dry granules
7) Mixing w/ lubricant
8) Tablet compression

76
Q

What are the steps of dry granulation?

A

1) Milling of drug and excipient
2) Mixing of milled powders
3) Compression into slugs
4) Screening of slugs
5) Mixing w/ lubricant
6) Tablet compression

77
Q

What are the steps of direct compression?

A

1) Milling of drug and excipient
2) Mixing of milled powders
3) Tablet compression

78
Q

What is the ideal hardness of a granule?

A

Hard enough to withstand handling and shipping but must disintegrate and/or dissolve in specified time

79
Q

What are the 2 types of tablet presses?

A
  • Single punch

- Multi-station rotary press

80
Q

When is a single punch tablet press used?

A
  • Small batches

- Laboratory instrument in product dev’t

81
Q

What is compression?

A

The process of pressing material to make it more firm and solid

82
Q

What is the force pattern complex?

A

An axial force causing compression and a radial force exerted by the die wall

83
Q

____ resists consolidation during compression

A

Frictional force btwn granule mass and die walls

84
Q

Are forces distributed uniformly throughout a granule mass?

A

No, regions of high density occur at the periphery due to movement of the material in a radial direction and friction along die walls

85
Q

What are the 2 events that occur in tableting process?

A

1) Reduction in bulk volume by elimination of air (compression)
2) Increase in mechanical strength of mass due to particle-particle interactions (consolidation)

86
Q

What is needed for a tablet to form?

A

Sufficient bond formation during consolidation

87
Q

What causes most of the problems in tableting?

A

Poor granulation

88
Q

What are some common tableting problems?

A
  • Binding or sticking
  • Picking
  • Capping
89
Q

What is binding or sticking of a tablet?

A

Tablets ejected w/ difficulty often accompanied by grunting sound

90
Q

What can cause binding or sticking of a tablet?

A
  • Inadequate or uneven lubrication of granules
  • Granules too dry or too wet
  • Die dirty or scratched
  • Worn die
91
Q

What is picking of a tablet?

A

Granule material sticks to the punch faces, laving the tablet w/ a pitted surface

92
Q

What can cause picking of a tablet?

A
  • Inadequate or uneven lubrication of granules
  • Granules under-dried
  • Scratched or damaged punch face
93
Q

What is capping of a tablet?

A

On decompression, top of tablet becomes detached

94
Q

What can cause capping of a tablet?

A
  • Worn tooling
  • Compression speed too fast
  • Excess fines
  • Punch fits too tightly into die
  • Excessive pressure
  • Insufficient or ineffective binder
  • Over-dried granules
  • Crystal habit of drug may have changed
95
Q

How is uniformity determined?

A

Weight variation if tablets are uncoated, tablets contain more than 50 mg of active drug, and if active component provides more than 50% of total weight

96
Q

What if a tablet doesn’t meet the criteria for weight variation uniformity testing?

A

Content uniformity testing must be done

97
Q

Describe the weight variation uniformity testing process

A
  • Weight 10 tablets and calculate content of active ingredient in each based on assay results (assume homogenous distribution of drug)
  • All tablets must contain 85-115% of labeled amount and relative standard deviation must not exceed 6%
  • If one unit is outside these limits, a further 20 tablets are weight
98
Q

When are the requirement for the weight variation uniformity test met?

A

If no more than one unit out of 30 is outside the 85-115% range and the RSD of the 30 tested does not exceed 7.8%

99
Q

What happens if the tablets do not meet the criteria for the weight variation uniformity test?

A

Content uniformity done by assay of 10 units individually and proceed as normal

100
Q

What does a disintegration test determine?

A

Time required for tablet to disintegrate in a specified test fluid at a specified temp

101
Q

Can disintegration results be extrapolated to bioavailability?

A

No, so dissolution testing is usually required

102
Q

What does the USP disintegration test consist of?

A

An apparatus into which 6 tablets are placed each into a cylindrical tube which is covered at the bottom by a 0.025 square inch wire screen

103
Q

Describe the USP disintegration testing process

A
  • Tubes are raised and lowered through a distance of 5.3-5.7 cm 29-32 times/minute
  • Disintegration complete when no solid material w/ a palpable core remains on the mesh
  • If one or two tablets fail, a further 12 tablets are tested
104
Q

When the conditions met for the USP disintegration test?

A

No more than 2 of the 18 tablets fail

105
Q

What does the USP dissolution test determine?

A

Time required for tablet to dissolve in a specified test fluid at a specified temperature

106
Q

Does dissolution have a correlation to bioavailability?

A

Yes

107
Q

What are the 2 types of apparatus’ used for dissolution tests

A

1) Apparatus consists of a 1000 mL glass vessel, a motor w/ a shaft and a cylindrical basket made of a metal screen (40 mesh)
2) Apparatus same except that a paddle is used in place of basket

108
Q

What should the mesh be made of?

A

Stainless steel or gold plated

109
Q

Describe the USP dissolution testing process

A
  • Glass vessel is filled w/ fluid and held at the specified temp
  • Tablet is placed into each basket or into the vessel if paddle is used
  • Rotation speed and time required for dissolution are specified in monograph
  • The quantity of drug which must be in solution w/in the time period is also specified in monograph
110
Q

What does the USP friability test determine?

A

How a tablet will withstand handling and general wear and tear

111
Q

What type of apparatus does the USP friability test use?

A

Apparatus w/ revolving drum which drops the tablet a specified distance a specified number of times

112
Q

Describe the USP friability testing process

A

5-20 tablets are weighed, placed in the apparatus, tested, and then re-weighed

113
Q

What is the requirement to pass the USP friability test?

A

Weight loss of no more than 0.8% after about 100 drops

114
Q

What are the units for hardness?

A

kg or kN

115
Q

How is hardness usually tested?

A

Tablet is placed on an anvil and force is transmitted to it by means of a moving plunger

116
Q

What does tablet hardness determine?

A

Ability of tablet to withstand shocks during handling and shipping

117
Q

What does hardness correlate w/?

A

Disintegration and dissolution

118
Q

What is hardness a function of?

A
  • Compression force during pressing
  • Particle density and size
  • Tablet shape
  • Components of formulation
119
Q

What is the usual minimum hardness for an uncoated tablet?

A

5 kg

120
Q

What are the 3 categories of tablet coating?

A
  • Sugar coating
  • Film coating
  • Compression coating
121
Q

What are the 2 basic processes for applying coatings?

A
  • Pan coating

- Air suspension coating

122
Q

What are coatings used for?

A
  • To mask unpleasant odors and taste
  • To protect an ingredient from decomposition
  • To improve product elegance
  • May be used to control release rate or at a particular portion of GI tract
123
Q

Good control over ____ is needed for sugar coating

A

Humidity, temp, and dust

124
Q

What are the processes involved in sugar coating?

A

Sealing, subcoating, syruping, finishing, and polishing

125
Q

Tablet cores usually represent about __% of weight of finished tablet

A

50%

126
Q

How is film coating accomplished?

A

Deposition of one or more film forming polymers on surface of tablet

127
Q

Usually film represents less than __% of finished tablet weight

A

5%

128
Q

What qualities should film forming materials have?

A
  • Soluble in solvent suitable for process and in GI fluids
  • Form strong continuous film that is smooth and elegant
  • Stable to heat, light, air, moisture, and drug in product
  • Have no appreciable taste, odor, or color
  • Able to support pigment or coating additives
  • Non-toxic
  • Crack resistant
129
Q

Non-enteric coating materials are usually _____

A

Cellulose derivatives

130
Q

Enteric coating materials are usually ____

A

Phthalate esters of cellulose

131
Q

What are common solvents used for coating?

A

Alcohols, esters, chlorinated hydrocarbons, acetone, and other ketones

132
Q

What occurs in compression coating?

A

Core is placed in center of larger die and surrounded w/ coating material in the form of free flowing granules, which is compressed into final product

133
Q

Is compression coating common? Why or why not?

A

No b/c of equipment required

134
Q

What can compression coating be used for?

A
  • Incompatible drugs

- Repeat-action tablets where first dose is coating and second dose is slower disintegrating core

Pharmaceutics Year 2 (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions