lecture 6 - tableting 1 MAIN TOPIC! Flashcards
what 3 essential characteristics must a tablet possess to be compressed
powder flowability
powder compressibility
powder compatibility
what is powder flowability
how can the flow be improved
The material can be transported through the hopper into the die to produce tablets of consistent weight and drug dose
Powder flow can be improved: addition of Glidant / or granulation (wet, dry)
what is powder compressibility
ability of a powder to reduce in volume under pressure and it occurs due to displacement of the gaseous phase
what’s powder compactibility
The property of forming a stable, intact compact mass when pressure is applied.
draw the diagram of tablet manufacturing
do it on a whiteboard !!
the choice of tableting method depends on
powder flowability
compressability
size of dose
compatibility
stability characteristics of the drug
What is a low dose drug going to be (what’s most of it)
so what do we need to check
less than 25 mg
most of it is excipients
need to check for content uniformity
What is a high dose drug going to be (what’s most of it)
so what do we need to check
more than 250 mg
most of it will be drug
need to check flowability and compatibility
Lower dose drugs are generally
Directly compressed
what is the 2 step process of direct compression
blend
compress it
form tablets
how to we compensate for compatibility and flowability in DC
add special direct compression fillers (filler binders)
how can we provide lubricity DC
addition of a die wall lubricant
how do we help with fluidity DC
add a glidant
how do we assure rapid disintegration DC
add a disintegrant
describe the general workflow of direct compression
raw material is blended
blended again
add external additives and lubricant
tablet manufacturing
then can be coated with sugar/ film coat
then we have the bulk drug product
what is the general formula for a direct compression tablet
preferentially a mix of
1 part drug
3 part filler-binder
a mix of plastically deforming & fragmenting material: Ratio 3:1
excipients can help with
with flowability / lubricity / disintegration
Example of super disintegrant
explotab
ac di sol
crospovidone
2-4 %
example of a disintegrant
starch 1500 (10-20%)
example of glidant
what method do we use to add the glidant into formulation
colloidal silica 0.2-0.5%
this is blend sieve blend method when adding glidant into formulation
example of lubricant
magnesium iterate 0.5-1%
what is the LAST set in tablet formulation
how long for?
LAST - DO NOT OVER MIX
(~5 min)
what are some advantages of direct compression
economical,
elimination of heat / moisture (increased stability)
optimised disintegration – no binder,
increased particle dissolution rate
batch to batch variation
fewer excipients
disadvantages of direct compression
content uniformity problems
segregation of low dose drugs
not practical for large dose drugs
if drug is fluffy = poor flow and compression
punch wear
dustiness
cost of new dc excipients = expensive
