Tablets - Ch 8 Flashcards
define tablets
solid dosage forms of medicinal substances that are usually prepared with the aid of suitable pharmaceutical adjuncts (excipients)
name 6 tablet variables
size
shape
weight
hardness
color
disintegration characterisitcs
which are more expensive – tablet or capsules?
capsules are more expensive.
thus, an advantage of tablets is that they are made at low cost
how can the bitter taste of tablets be masked?
through sugar coating or film coating
true or false
tablets have a narrow range of drug release
FALSE – they have a broad range of drug release
they can be immediate release, delayed release, controlled release, etc
true or false
tablets have a possibility of variable dosage strength, which is an advantage
true
true or false
a disadvantage of tablets is that they are not precise and accurate with their dosing
false - they are precise and accurate with their dosing
which have a longer shelf life – tablets or liquids?
tablets have a longer shelf life. thus, an advantage of tablets is that they are durable and stable
true or false
tablets are convenient to handle and administer
true
it is difficult to formulate tablets for what kind of drug?
a water insoluble drug for large doses
true or false
a disadvantage of tablets is that children and the elderly may have difficulty swallowing it
true
what kind of drugs CANNOT be compressed to form tablets
those with an amorphous nature, that flocculate, and that have a low density
true or false
an advantage of tablets is that they can be extemporaenously prepared
FALSE - they cannot (be prepared spur of the moment)
what is another name for diluent?
what are the requirements for it to be included in the tablet dosage form?
diluents/fillers add the necessary bulk to the formulation
must be:
-able to be compressed
-physically and chemically stable
-compatible with the pt population
what is another name for binders and what is the purpose of it in the tablet dosage form?
binders/adhesives
add cohesive properties to the tablet. promote adherence of the particles in the formulation
true or false
binders are added as dry powders into the formulation
true
what is the concern with binders/adhesives?
it may decrease dissolution and solubility and promote complexation
what is the most common disintegrant/disintegrating agent in the tablet dosage form
corn starch/potato starch
what is the function of disintegrants in tablets
promote the breakup of tablets after administration into smaller particles that are ready for availability
when in the tablet making process are disintegrants added?
during and after granulation
explain the action of disintegrants
swelling and capillary action to ensure disintegration
what is the “oil to the system” in tablet formulation?
lubricant
glidant
antiadherent
lubricant agents
too much of antiadherents/glidants/lubricants/lubricating agents can cause what?
waterproofing
reduces friction with the tablet machine
lubricant
what does a glidant do?
allows the flow of the granulation or powder mixture
name some miscellaneous adjuncts that are added in tablet formulation
colorants
flavorants
sweeteners
when is the coating of tablets done?
after the tablet is made
for the COLOR of tablets, what kind of colors are more attractive?
pastels
what is the most common diluent for tablets
lactose
what is the most convenient type of tablet to make and is most common
compressed tablets
how are compressed tablets prepared?
are they coated or uncoated?
prepared by a single compression of the formulation (drug + excipients).
high pressure application using steel punches and dies, to powders or granules
they are GENERALLY uncoated but they may get sugar or film coating after compression
what are hypodermic tablets?
not used anymore
used to be tablet triturates that were used by physicans in the extemporaenous (fast – as needed) preparation of parenteral solutions
of tablets would be dissolved in suitable vehicle for injection
what are dispensing tablets
like hypodermic tablets, also not used anymore
they were NOT dispensed to the patient
it was a convenient quantity of a potent drug used by the pharmacist to compound a prescription for other dosage forms like powders or liquids
were dangerous in that they might accidentally be dispensed to patients
what are multiple compressed tablets?
prepared by more than single compressions – usually contains 2 or 3 layers and each layer contains a diff drug or inert excipient OR layers contain the SAME DRUG but provides a different release profile due to diff formulation
give 3 reasons for multiple compressed tablets
incompatability between drugs
desire to have the drug release in stages
to provide color coding ot a unique appearance
as mentioned, one of the reasons for mutliple compressed tablets is the incompatibility of drugs
give an example of when this would be the case
if there is an anionic and cationic dru
one of the reasons for multipls compressed tablets is so that the drug can release in stages
give 2 examples
to provide repeated action
to provide prolonged action
one of the reasons for multiple compressed tablets is color coding or a unique appearance
give 2 ex
for product identification
for aesthetic appeal
for multiple compressed tablets, which is more common —
-a core of one drug and a shell of another
-a layered tablet of 2 drugs
layered tablet of 2 drugs is more common
the core or one drug and shell of another is more difficult to make
what are sugar coated tablets?
compressed tablets which are coated with colored or uncolored sugar(s)
true or false
sugar coated tablets are compressed tablets coated with uncolored sugars
false – sugar may be colored or uncolored
true or false
sugar coating dissolves QUICKLY in GI fluids to release the drug
true - the sugar coating is water soluble
name 3 reasons for adding sugar coating to a compressed tablet
-enhance aesthetic appeal
-mask the unpleasant taste or odor
-enhance stability by protecting the drug agaonst degradation by air, humidty, and radiation
true or false
sugar coating can enhance stability
true - protect against degradation brought on by air, humidity, radiation
name 4 disadvantages of sugar coated tablets
time consuming
expensive
requires specialized expertise
increases the tablet weight and size by up to 50% or more
1 of the disadvantages of sugar coated tablets is that it is time consuming to make. how long?
at least a week
true or false
the addition of sugar coating to tablets may make it hard to swallow
true – due to weight and size increase
how are film coated tablets prepared
by coating a COMPRESSED TABLET with a thin layer of either water soluble or water insoluble POLYMERIC film
sugar coated was eventually somewhat replaced with film coating. why?
due to advancements in polymeric science
what is the film used in film coated tablets?
water soluble or water insoluble polymers
HPC (hydroxypropyl cellulose)
HPMC
EC
name 2 reasons for film coated tablets
-to protect the drug against atmospheric degradation by air. humidty, radiation (same as sugar coating)
-sometimes, to alter the dissolution profile
explain how film coated tablets can alter the dissolution profile
changing the functional groups on cellulose groups is done to alter the water solubility
if the polymer used for the film coating is 100% water soluble, the drug will release in the stomach
if 50%, only 50% will be released in the stomach
totally water insoluble is not good bc it won’t release at all in the GI
which is less time consuming and less difficult to apply - sugar coating or film coating?
film coating – takes a few hours
sugar coating takes at least a week
which coating has WORSE mechanical strength - sugar or film coating?
sugar coating
which coating is elastic and flexible - sugar or film coating
film coating
true or false
most tablets are film coated
true
for which coating is it difficult to make an automated and continuous process - sugar coating or film coating
sugar coating
easy for film coating
Which coating causes LITTLE increase in tablet weight and size
film coating
what is Gelcap
a capsule shaped COMPRESSED TABLET that has a gelatin coating
what are some advantages of gel cap?
-gelatin coating facilitates swallowing
-more tamper evident than an unsealed capsule
-coated product is about a third smaller than a true capsule filled with the same amount of powder
-does not need disintegration test bc it is a loose powder
true or false
unsealed capsules are more tamper evident than gelcap
FALSE
gel cap is more tamper evident
enteric coated tablets have ______ release features
delayed
how are enteric coated tablets prepared?
by coating a COMPRESSED tablet with polymeric materials which RESIST DISSOLUTION OR DISRUPTION IN ACIDIC ENVRIONMENT of gastric fluids, but does NOT resist dissolution or disruption in the intestines
enteric coating is designed to dissolve where?
only in the INTESTINAL fluid where the pH is slightly acidic to alkaline
true or false
in enteric coated tablets, the majority of the drug is absorbed in the small intestine
true
name 2 reasons for enteric coated tablets
to protect an acid labile (unstable) drug from the gastric fluid
-to bypass the stomach if doing so will enhance the drug absorption from the intestines to a significant extent
true or false
enteric coated tablets are related to water solubility
false - related to pH
true or false
both enteric and film coated tablets are made with a polymeric material
true
what are buccal tablets?
intended to be eroded/dissolved SLOWLY in the buccal pouch. used where slow absorption of the drug is intended
where are sublingual tablets intended to be dissolved
beneath the tongue, for absorption through the ORAL MUCOSA. they dissolve promptly to give RAPID drug effects
true or false
buccal tablets provide rapid effects while sublingual tablets erode slowly
false - opposite
what is the IDEAL duration for a buccal tablet?
what is the reality?
ideal - 24 hours so it only has to be used 1 time a day
however, 6-8 hrs is the reality time bc we have to eat
for both buccal and sublingual tablets, what is an imperative counseling point to the patient
DO NOT SWALLOW THE SALIVA
the dose is not designed for stomach absorption
name 3 reasons for buccal and sublingual tablets
-protect a drug that is destroyed by GI fluid
-protect the drug from extensive 1st pass effect
-provides better absorption of the drug from the ORAL MUCOSA that is poorly absorbed by the GI tract
explain chewable tablets
designed to be chewed rather than swallowed
this brings about a smooth and rapid disintegration of the tablet which yields a creamy base in the mouth
what is the choice if DILUENT for chewable tablets and why?
mannitol bc it provides a pleasant taste and a cooling sensation– palatability
effervescent tablets are designed to do what?
to dissolve with effervescence (bubbles) when placed in water
this is the result of the reaction between tartaric and/or citric acid and the alkali metal of bicarbonates
carbon dioxide forms from this reaction and acts as a DISINTEGRATOR and produces effervescence which speeds up dissolution and enhances palatability
give 2 examples of effervescent tablets
alka seltzer
effervescent aspirin tablets
true or false
effervescent tablets form carbon dioxide which acts as a DISINTEGRATOR and hastens dissolution and enhances palatability
true
give 2 reasons for effervescent tablets
increase palatability
provides immediate relief due to the increased dissolution rate form the effervescence produced by carbon dioxide
in effervescent tablets, how is carbon dioxide produced?
reaction between tartaric acid and/or citric acid with an alkali metal or bicarbonates
true or false
effervescent tablets are placed in water
true
