introduction to medicinal products part 2 Flashcards
examples of powdered dosage forms?
effervescent powders (contain the drug, acid carbonate)
dusting powders (applied topically)
powders for syrup (for those difficulty swallowing)
why does segregation or de-mixing happen
size and density differences
how to prevent segregation?
granulation
what gives a good granulation
granules with correct ratios and narrow particle size distribution
why is preventing segregation important?
ensure patient receives same dose of API every time
pros of using powders/granules?
more stable than liquid preparations therefore increased shelf life
more convenient for drugs with high dosage
faster dissolution rate compared to tablets
cons of powders/granules
less convenient for patient to carry
not convenient for low dosage drugs
not suitable for drugs that are inactive in the stomach
can cause stability problems
why are tablets sometimes used over powders
convenient to handle
more stable
how is a tablet formed
hopper fills die with powder
upper punch lowered compressing the powder into a tablet
tablet ejected
What do powders, tablets, and capsules have in common?
they need dissolution to happen to be effective i.e need to be in a solution to be absorbed- molecularly dispersed form
what is the rate of dissolution?
the rate at which drug particles becomes drug molecules diffused into solvent
one way of the dissolution of a saturated solubility of solid increased?
addition of excipients
what is the role of a disintegrant?
makes sure the tablet breaks into fragments when in contact with liquid by facilitating water uptake or rupturing tablet by swelling
examples of disintegrant?
cellulose, starch
what is the role of dissolution enhancer?
required if drug has low aqueous solubility (dissolution is the rate limiting step) so temporarily increases solubility
examples of dissolution enhancer?
magnesium oxide
what is the rate of dissolution effected by?
excipients present
what are the kinds of release?
immediate release- drug released rapidly after being taken
modified release- prolonged, pulsatile, delayed
difference between prolonged, immediate and delayed release
refer to introduction of medicinal products part 2 slide 16
what is pulsatile release?
tablets released in two or more pulses
what coating is used for tablets with delayed release?
enteric coating
what is enteric coating
polymers that are insoluble in acid but dissolve in neutral/ slightly alkaline conditions in the gut
characteristics of hard capsules?
have a cap and a body (shell)
colour aided for identification
what is the shell of a capsule for
to hide hide mask the taste of the filling
what can hard capsules be filled with?
non aqueous liquids or dry solids
relationship between shell and the contents?
they shouldn’t interfere with each other
what must a good hard capsule be able to do?
the shell should dissolve rapidly in gastrointestinal fluids
contents in shell should disperse rapidly
how is dissolution rate increased in a capsule?
by adding excipients
why is dissolution rate faster with excipients
if the contents of the capsule have a more porous mass there’s an increase in surface area so dissolution rate is faster
what do soft capsules contain?
liquid or semi-solid
difference between hard capsule and soft?
shell in one piece for soft
where is the drug contained in a soft capsule?
in solution or suspension in the matix
Hydrophobic matrix example
triglyceride vegetable oils
hydrophilic matrix example
polyethylene glycol
what is the shell of soft capsule made of?
gelatine, plasticizer, water
