Pharmaceutics

Question 1

Describe sugar coated tablets

Answer 1

Multiple layers at least 15 sugars applied

tablet must be round

Question 2

explain the process of tablet manufacturing

Answer 2

1. ) powder/granule must be mixed well
2. ) powder/granule must flow well from hopper to press
3. ) powder/granule must not separate between hopper and press
4. ) powder/granule must be compressed into tablets
5. ) tablets must withstand further treatment e.g. coating, packaging, transport

Question 3

what are constituents of tablets?

Answer 3

1. ) drug
2. ) Diluent e.g. lactose monohydrate
3. ) compression aid e.g. Microcrystalline cellulose
4. ) Binder e.g. PVP
5. ) Disintegrant e.g. Pregelatinised starch
6. ) Lubricant e.g. Magnesium stearate
7. ) Glidant e.g. talc
8. ) Colour and flavouring
9. ) Acidity regulator e.g citric acid
10. ) surfactant to improve dissolution

Question 4

What are formulation techniques for tablet?

Answer 4

1. ) Direct compression
2. ) Wet granulation
3. ) Dry Granulation
4. ) Roller compaction

Question 5

summarise direct compression technique

Answer 5

mix the drug and excipients
lubricate the powder mix
compress into tablets
low shear mixing equipment needed (cheap)

Question 6

in direct compression why do all excipients need to be spray dried except the lubricant?

Answer 6

to ensure sphericity
to improve mixing
to improve flow characteristics

Question 7

give an example of a disintegrant

Answer 7

pregelanitised starch

Question 8

give an example of a compression aid

Answer 8

microcrystalline cellulose

Question 9

give examples of lubricants

Answer 9

magnesium stearate
stearic acid
sodium stearyl fumarate

Question 10

give examples of diluents

Answer 10

lactose monohydrate
dibasic calcium phosphate
mannitol - cool taste
sorbitol - non-sugar

Question 11

what bonds holds the tablet together?

Answer 11

non-covalent adhesive forces between the particles van der waals, london.

Question 12

compression characteristic - brittle fracture what does it increase?

Answer 12

brittle fracture increases total particulate surface area

produces stronger tablets

Question 13

compression characteristic - plastic deformation

Answer 13

it doesnt increase surface area
produces weaker tablets
no dissolution problems
powder compressed into tabs
tabs remain intact when pressure is applied
particles elastically return back to original state once pressure is not there

Question 14

which constituents show brittle fracture

Answer 14

lactose monohydrate

dibasic calcium phosphate

Question 15

which type of compression characteristic does microcrystalline cellulose?

Answer 15

Elastic Deformation

Question 16

describe ordered mix

Answer 16

small drug particles adhered to larger carrier particles
used in dry powder inhales
not used in tabletting

Question 17

advantages of direct compression

Answer 17

quickest method
lowest time and labour cost
no heat involved
no water/solvents involved
lubrication done in same vessel as mixing-reduces transfer loss

Question 18

disadvantages of direct compression

Answer 18

more expensive excipients required
relies on drug being easily mixed
segregation issues due to vibration

Question 19

describe wet granulation technique

Answer 19

1. ) dry mix the drug/powder
2. ) add granulation fluid to mixed powder to form wet granules
3. ) dry the wet granules- remove liquid keep granule structure
4. ) mill the dried granule to remove large lumps
5. ) lubricate the milled granule
6. ) compress into tablets

Question 20

what is an example of super disintegrant

Answer 20

sodium starch glycollate

croscarmellose

Question 21

what is an example of granulation fluid

Answer 21

water

ethanol

Question 22

what holds the granules together in Wet Granulation?

Answer 22

solid bridges from wet binders e.g. PVP

NON-covalent adhesive forces e.g. van der waals, london forces by INTRA-GRANULARLY

Question 23

What happens when there is too much granulation fluid?

Answer 23

overwetted granule which will result in dissolution of the granule

Question 24

wet granulation- End point detection

Answer 24

Stop the process periodically and squeeze the granule
• Granule should feel slightly damp, not wet or soggy
• Granule should hold together after squeezing (like a cake)
• Should be able to “snap” granule block in two
• Old-fashioned method
• Difficult to feel texture of granule through gloves, but
often the only method applicable on a very small scale
• Can’t do this on production scale with enclosed equipment

Question 25

if a tablet has low solubility and is very strong which distegrant should you use

Answer 25

superdisintegrant to speed tablet disintegration

Question 26

Advantages of Wet granulation?

Answer 26

reduces mixing and segregation issues
best for low dose drugs
film coating is way easier compared in direct compression
Wet granulation is the choice always if possible

Question 27

Disadvantages of Wet Granulation

Answer 27

more steps than direct compression
more chance of things going wrong
water/solvents needed which is not good for water sensetive drugs
heat required

Question 28

Explain the process of Dry Granulation

Answer 28

Mix the drug and excipients
compress to form large tablets more than 1 diameter
Mill the tablets to produce dry granules
lubricate granule if needed
compress into tablets

Question 29

advantages of dry granulation

Answer 29

no heat or solvents used

cost effective

Question 30

disadvantages of dry granulation

Answer 30

may have powder flow issues
more processing steps needed
final tablet softer compared to wet granulated tablet

Question 31

explain the process of Roller compaction (Chilsonation)

Answer 31

Mix the drug and its excipients
compress powder mix between two rollers to produce ribbon
mill the ribbon to produce dry granule
lubricate if needed
compress into tablets
COMPLEX!

Question 32

advantages of roller compaction

Answer 32

cost effective

no heat or solvents used

Question 33

disadvantages of roller compaction

Answer 33

specialised equipment required
might have powder flow issues
softer tablets produces
dusty operation