Tablets Flashcards
1
Q
What is the physical description of molded tablets?
A
Soft, soluble and designed for rapid dissolution
2
Q
How is molded tablets prepared?
A
They are prepared with molding rather than by compression
3
Q
When is an inappropriate situation to use molded tablets?
A
For potent drugs due to difficulties with content uniformity
4
Q
What does molded tablets not contain?
A
Disintegrates
Lubricants
Coatings
5
Q
Explain the process of molding
A
Powder blend is moistened with hydroalcoholic solvent
Molded under pressure lower that compression
Solvent is removed by air during
6
Q
Definition of chewable tablets
A
Intended to disintegrate in the mouth
7
Q
What is the primarily intent for chewable tablets?
A
For children who prefer chewing a flavoured medication
8
Q
Advantages of Chewable tablets
A
Pleasant taste
No bitter or unpleasant aftertaste
Convenience and pt acceptance
Rapid onset of bioactivity
9
Q
What is the limitation of chewable tablets?
A
Number of drug that can be put into chewable tablets
10
Q
What is the most common excipient in chewable tablets?
A
Mannitol
11
Q
What makes mannitol better for chewable tablets
A
70% sweetness compared to sucrose
Cool taste and mouth fell
Non-hydroscopic
12
Q
What is used for sugar free chewable tablets?
A
Xylitol
13
Q
What is important counselling point for chewable tablets?
A
Do not swallow whole
Chew to break the tablet
14
Q
Examples of Chewable tablets
A
antacids – Maalox, Tums
vitamins – Vitamin C, calcium
analgesics - aspirin – children’s chewable – often used for pets, acetaminophen
Anticonvulsant: carbamazepine
Angina pain medication: Isosorbide dinitrate*
antibiotics – amoxicillin
15
Q
Define effervescent tablets
A
Large wafer like tablets which dissolve rapidly in water
16
Q
What is the benefit of effervescent tablets?
A
Large surface area allows for faster rate of solution
17
Q
What is released when effervescent tablets are breaking up?
A
Carbon dioxide generated from sodium bicarbonate and citric or tartaric acid
18
Q
When is the chemical reaction initiated with effervescent tablets?
A
When it is placed in water
19
Q
What is important considerations of effervescent tablets?
A
Binders, fillers and lubricants are water soluble
Moisture excluded during manufacturing
Packaged in moisture-proof containers to avoid degradation
Tablets individually wrapped in foil strip or wrapped and stacked in tubes
Flavoured & sweetened
20
Q
Examples of effervescent tablets
A
Vitamin C
Calcium
Alka-seltzer
21
Q
Important counselling for dispensing effervescent tablets?
A
Dissolve in water at room temperature
Once effervescence stops, wait >5 min and stir the solution for about 10 seconds then drink
Store away from humid conditions
22
Q
Where is the tablet placed for sublingual tablets?
A
Under the tongue
23
Q
Where is the tablet placed for buccal tablets?
A
In the side of the cheek
24
Q
What is the purpose of sublingual tablets?
A
Designed to produce an immediate systemic effect by enabling drug to be directly absorbed through the oral mucosa
25
What is general physical description of sublingual tablets?
Are small, soft and flat
26
What is the purpose of buccal tablets?
They are designed to erode relatively slowly
27
What is RDT and ODT?
Rapidly dissolving tablets
Orally disintegrating tablets
28
What is the difference between sublingual and buccal tablets?
Require more than a minute to dissolve in the mouth
29
FDA definition of RDTs
A solid dosage form containing medicinal substances, which disintegrates rapidly, usually within a matter of seconds when placed upon the tongue
30
What is the benefit of ODT?
Enchanted clinical effects through pre-gastric absorption front eh mouth, pharynx and esophagus
Increase the bioavailability
31
What is done in packaging to protect ODT from moisture?
Packaged in blister packs
32
Patient information for ODT
Do not try to administer tablets with wet hands
Store tablets in a dry place
Certain products may cause a burning or prickling sensation on the tongue
33
Challenges of ODT and (sublingual)
Drug loading
Taste masking and palatability
Friability
Extra cost of packaging
34
What is the challenge of friability?
Balance difficult to maintain a between friability and speed of dissolution
35
What is benefit of lozenges
Promote saliva flow (which is soothing)
May be used for systemic effect (if absorbed by buccal lining)
36
Examples of lozenges
Fentanyl (lollipop)
Nicotine
Sore throat
Flurbiprofen
Zinc
37
What patients who lozenges are useful for?
Difficult swallowing
Paediatric pt
Geriatric pt
Pt with GI blockage
38
How are lozenges prepared?
Prepared by molding or compression
39
What is another name for molded lozenges?
Pastilles
40
What is another name for harder lozenges?
Troches
41
Compressed lozenges are different
They are harder
So they will slowly dissolve or disintegrate
42
What is the basic properties of a good lozenge?
Slow uniform dissolution or erosion over 5-10 minutes period
Smooth surface texture
Pleasant flavour masking drug taste
43
What are some therapeutic use for lozenges?
local anaesthetics (benzocaine)
antiseptics/antimicrobial
antitussives (cough drops)
decongestants
Antihistamines
anti-nausea
analgesics
44
What are the ingredient in a compounded lozenges?
Sugars to form a hard lozenge
PEG to form a soft lozenge
Gelatin to form a chewable lozenge
45
Composition of hard lozenges
Might be considered solid syrups
46
What is the percentage of sucrose and corn syrup for hard lozenges?
55-65% sucrose
35-45% corn syrup
47
What is a critical step for hard lozenges?
To follow all formation instructions and pay particular attention to temps
48
Is hard lozenges high or low moisture content?
Low (0.5-1.5%)
So the water is evaporated off by boiling the sugar mixture during the compounding process
49
What is the benefit of soft lozenges?
Can be hand rolled
Then cut into pieces which contain the correct amount of active ingredient
More convenient dispensing method
50
What is the composition of soft lozenges
PEG 1000 or 1450
Chocolate
Sugar acacia base
Silica gel
51
What is acacia
Used to add texture and smoothness
52
What is silica gel
Used as a suspending agent to keep materials from settling to the bottom of the mold cavity during the cooling process
53
What should be changed in the compounding steps if using PEGs?
The mixture will need to be overfilled as PEG contract once cooler
54
What is the composition of chewable lozenges?
Glycerinated gelatin suppository formula which consists of glycerin, gelatin and water
55
What is capping?
The partial or complete separation of the top or bottom crowns of a tablet from the main body of the tablets
56
What is lamination?
The separation of a tablet into 2 or more distinct layers (transverse cracking and separation of tablets)
57
List the causes of lamination/capping
Air entrapment in light and fluffy powders
Excessive “fines”
Too little moisture in granulation
Weak granules or too weak a binder
Improver adjustment of machinery
58
What is picking?
The surface material from a tablet that is sticking and being removed from the tablet surface by a punch
59
What is sticking?
Tablet material adhering to the die wall
60
List causes of picking/sticking
Inadequate lubrication
Insufficiently dried wet granulation
Poor finish on punch surfaces
61
What is whispering?
Fine edge attached but not broken off tablet
End up with high friability values since whiskers are removed in friability testing
62
List causes of whiskering
Especially deep concave punches
Punches worn and in poor condition
63
What is chipping/splitting?
Tablet either chipped or split in half
64
List causes of chipping or splitting
Poor finish or worn punches and dies
65
What is friability?
The ability of the compressed tablet to withstand abrasion or crumbling in packaging, handling and shipping
66
List the causes of friability
Inadeqaute bonding of tablet mix
Too much or too little pressure
Worn punches or dies
67
List causes of poor disintegration
Tablets hardness too high
Low amount of disintegrant
Too much binder
Over lubrication causing “waterproofing”
68
What is mottling?
An unequal or uneven distribution of colour on or in a tablet
69
List the causes of mottling
Uneven distribution of powdered lakes
Soluble dye migration during drying
70
What is low hardness?
Can lead to rapid release of drug from form or tablet will be too fragile for shipping and handling
71
List causes of low hardness
Compression pressure too low
Binder can affect the hardness of a tablet
72
What are some traits of tablets?
Solid dosage forms
Prepared by compression or molding
Contain on or more medicinal substances
73
What are some parts in a tablets?
Drug
Diluents
Disintegrants
Colourants
Coating
Binders
74
What is the prep stages of compressed tablets?
Powders
Compression
Tablets
75
What is the problem with compressed tablets?
Simple powders may have poor flow and compression characteristics
They require tremendous pressure and the resulting tablet may not have desired characteristics
76
What is the solution to the main problem of compressed tablets?
Materials to be compressed usually require some modification such as formation of granules (helps with cohesive and flow)
77
Define granulation
The process of particle size enlargement of powdered ingredients
78
What is the commonly used processed methods?
Wet granulation
Dry granulation
79
What is the advances in the wet granulation process?
Fluid bed granulator
Microwave vacuum processing
80
Explain fluid bed granulator
Whole process in one machine through fluidized air movement
81
Define microwave vacuum processing
Use of microwaves reduces the drying time by one fourth
82
What is another name for diluents?
Fillers
83
Purpose of diluents
Acts as a vehicle/carrier for the drug
Increase the bulk of the tablets
Help improve or maintain content uniformity
Diluents comprise from as little as 5% to as much as 80% of total weight
84
Examples of diluents
Lactose
Dextrose
Starch
Mannitol
Microcrystalline cellulose (MCC)
85
What is a binder?
Often considered the most critical ingredient
They impact cohesiveness to powders therefore providing the necessary bonding to form granules which are then compacted into tablets
86
Explain how the amount of binder is critical
Sufficient binder is necessary to maintain an intact tablet during transit , dispensing and handling
Concentration range varies from 1 to 20%
87
What percent is diluents?
5-80%
88
What percentage is binders?
1-20%
89
Examples of binders
Starch
Gelatin
Glucose
Polyvinylpyrrolidone (PVP)
90
Can tablet excipients work as more than one function?
Yes
91
What does dextrose, sucrose and lactose do?
They exhibit binding properties
92
What two functions can starch and MCC have?
Binding and disintegrate properties
93
What functions can lactose and sucrose both have?
Impact hardness
94
What does starch, kaolin and dextrose add?
Softness
95
What does mannitol, lactose and sorbitol add?
A cooling effect
96
What is the properties that lubricants add?
Gliding effect
Anti adhesive effect
Acts as lubricant
97
Explain gliding effects
Provide by coating and lubricating particle surfaces
This helps improve flow properties of tablet granulation
98
Explain anti-adhesive effects
Prevents adhesion of materials to punches and dies during tablet compression
99
Explain why lubricant is needed
It is need between walls of die cavity and tablet
Helps to facilitating tablet ejection
100
List examples of lubricants
Magnesium stearate
Stearic acid
Talcum
101
What percentage is lubricants?
<1 %
102
What is the purpose of disintegrants
Facilitates the break-up of a tablet after administration
Causes the tablet to rupture or break apart when it comes in contact with the aq fluid of the GI tract
Facilitates disintegration, dispersion and dissolution of tablets
103
Mechanism of disintegrants
Involves porosity, capillary action and swelling
It is believed to draw gastric fluids into the tablet, causing porosity in the tablet or swelling and finally break up due to hydrostatic pressure
104
Examples of disintegrants
Starch
Microcrystalline cellulose
Sodium bicarbonate & citric/tartaric acid
105
Function of colouring agents
To enhance esthetician quality
To provide distinctiveness to the product/ to aid in product identification
Colourants must be approved by regulatory bodies
106
Function of flavouring agents
to make it taste better for better compliance
107
What are required for chewable and effervescent tablets?
sweeteners and flavoring agents
108
What are some examples of flavoring agents?
peppermint
vanilla
cherry
109
What is the purpose of moleded tablets?
makes soft, easily disintegrating tablets
designed for rapid dissolution
110
Why should combining with calcium salts with tetracycline?
it interferes with absorption of tetracycline from the gut
111
What the preparation of a compressed tablets?
prepared by compression using tablet presses the basic mechanical unit is a punch and die set
112
What does the basic mechanical unit for tablet compression consists of?
lower punch
upper punch
die
113
Explain the feeder
transfer of granules into position in the die cavity
114
Explain the metering
leveling of the granule/powder contents in the die, removal of extra granules
the position of the lower punch in the die is responsible for the volume of the cavity which is adjusted depending on the weight of the granules
115
Explain of compression
top and bottom punches come together by pressure within the die to form the tablet
as this stage approaches, the top and bottom punches move between two large wheels called compression rolls
the distance between top and the bottom punches define the thickness and hardness of the tablet
116
Explain the ejection
the upper punch retracts from the die cavity, the lower punch rises in the die and pushes out the tablet
then by the scrapper tablets are collected in the container
117
What is the purpose of tablet coating?
smooth surface
product identification
mask drug taste
improve drug stability in the tablet
118
What are some functions of coating?
enteric coating
controlled/sustained release
119
Types of Tablet coatings
sugar coating
film coating
functional coating
120
Potential problems with sugar coating
many steps of this process involve tumbling -tablets must be hard enough to withstand it
must mix uniformly or coating goes on unevenly resulting in tablets of different sizes and weights
121
What is the common coating?
film coating
122
What is the film coating process?
tablets move through a zone where the coating material is applied
via a coating pan, spray in a fluidized stream, or press coating
123
Factors of Mixing of Tablet mass
pan shape, rotational speed and loading affect the mixing of tablets and coating
124
What is essential to deposit the same quantity of film?
uniform mixing
125
What can cause unacceptable color uniformity?
poor tablet movement in coating pan
126
What is a compression coating?
compaction of a dry coat around a tablet core, produced on the same tableting machine
127
What is used to create a layered tablet?
compression coding
128
Is organic or aqueous film coating preferred? Why?
Aqueous is preferred because organic is expensive and sometimes not environmentally friendly
129
What are some challenges when it comes to aqueous film coating?
slow evaporation of water
orange peel effect
bridging
tablet erosion
130
What is the orange peel effect?
roughness of coating on tablet surface due to failure of spray droplets to coalesce
131
What is bridging?
covering of score line or monogram on the tablet due to longer drying times
132
What is tablet erosion?
disfiguration of the core tablet when subjected to the coating solution for too long
133
Explain enteric coating
allows for disintegration in the intestine rateher than the stomach
could be a type of film coating
134
Explain CAP
cellulose acetate phthalate is the most common material used in enteric coating
135
Explain Functional Coatings
allow for timed release can have particles coated with varying thickness of coating so drug is released gradually from the dosage unit
136
What are some physical features of tablets?
general appearance
size
shape
organoleptic properties
137
What are some factors of general appearance of tablets?
texture
scoring
engraving
138
What are some factors of size of tablets?
diameter & thickness
139
What are some factors of shape of tablets?
oval
oblong
triangular
flat
140
What are some factors of organoleptic properties?
color
odour
taste
141
What are some other important physical specifications of tablets?
tablet weight
thickness
hardness
disintegration
content uniformity
drug dissolution
142
What are some tests for tablets?
tablet hardness
friability test
drug content uniformity
drug release
143
Explain tablet hardness test
a function of die fill and compression force
tablets should be sufficiently hard. toresists breaking or chipping during packaging shipping and normal handling yet soft enough to disintegrate or dissolve properly after administration
144
Define tablet hardness
as the force required to break a tablet in a diametric compression test
145
Explain friability test
tablets are allowed to roll and fall within a rotating tumbling apparatus
tablets are weighed before and after a specified number of rotation and the loss in weight is determined
146
Define friability test
ability of tablet to withstand abrasion in packaging, shipping and handling
in other words its tendency to crumble
147
What are the two drug content uniformity test?
weight variation
content uniformity
148
Explain the weight variation test
Relies on tablet weight to assess the amount of drug in each unit
The greater the amount of drug the more accurate the method is
149
Explain the content uniformity
Assesses uniformity of content by assaying each dosage unit
Needs to be around 15% range within a relative standard deviation of <6 %
150
The importance of dissolution test
Since drug absorption and bioavailability are dependent upon the drug being dissolved state
151
The purpose of the dissolution testing
Shows that
The release of the drug from a dosage form is around 100%
The rate of release is uniform from batch to batch
The rate of release is the same as the release rate from those batches proven bioavailability and clinically effective
152
When is the dissolution testing useful?
In the early stages of drug development & formulation to optimize the dosage form characteristics
153
What two drug release test need to be performed?
Disintegration and dissolution
154
What is the measure of a pass or fail of disintegration?
Six tablets are agitated in a given medium (water) at 37 C
The tablets must disintegrate within a specified time period
155
What is disintegration tests used for?
As a mean to ensure that there is batch to batch consistency with respect to disintegration
