oral powders and tablets

Question 1

how are tablet forms more convenient for the manufacturer

Answer 1

• more stable than liquid
• easy to scale up
• versatile machinery

Question 2

why are tablets convenient for the patient

Answer 2

• accurate dosage
• easy to take
• easy to carry
• release rate can be controlled

Question 3

what has to happen to products with low flowability before they can be made into tablets

Answer 3

they have to go through the granulation process

Question 4

what are excipients

Answer 4

they are pharmacologically inert materials that are added to pharmaceutical dosage characteristics.

Question 5

can excipients affect the bioavailability of the active ingredient

Answer 5

they might

Question 6

can excipients be swapped around

Answer 6

no, they are biologically inert

Question 7

what does bio inert mean

Answer 7

it doesn’t invoke a response or interact with biological tissue

Question 8

what are fillers (aka dilutents) used for

Answer 8

to add the necessary bulk

Question 9

what is the min weight a tablet must be

Answer 9

over 50mg

Question 10

common water soluble fillers

Answer 10

lactose
glucose
mannitol

Question 11

common water insoluble fillers

Answer 11

cellulose

Question 12

what do binders (aka adhesions) do

Answer 12

promote adhesion of the particles

Question 13

examples of solution binders

Answer 13

• starch
• sucrose
• gelatin
• PVP
• cellulose derivatives

Question 14

dry binder examples

Answer 14

microcrystalline cellulose

Question 15

what do glidants do

Answer 15

they improve flowability and reduce friction between particles

Question 16

glidant examples

Answer 16

• colloidal silica
• talc

Question 17

what do lubricants do

Answer 17

they reduce the friction between the particles and the die wall and makes sure they don’t stick during compression process

Question 18

examples of lubricants

Answer 18

• fluid lubricant
• magnesium stearate

Question 19

how does magnesium stearate work

Answer 19

it has a hydrophobic tail which coats the particles and makes sure they don’t stick to surfaces

Question 20

can magnesium stearate change the properties of a tablet

Answer 20

yes and can make it take longer for them to dissolve

Question 21

what do disintegrants do

Answer 21

they promote breakage into smaller particles after administration

Question 22

examples of disintegrants

Answer 22

starch

Question 23

how do disintegrants work

Answer 23

they expand when exposed to water and pushes the tablet apart

Question 24

other excipients

Answer 24

• colourants
• flavouring agents
• sorbents

Question 25

what are sorbents

Answer 25

compounds which absorb water meaning it prevents hydrolysis or delays it

Question 26

what are the three steps of tablet formation

Answer 26

1. filling 2. compression 3. ejection

Question 27

what happens on decompression when using elastic material compared to plastic

Answer 27

elastic material will expand whereas plastic material will not

Question 28

what effect does compression have on the content

Answer 28

- pores number decreases - pores size decreases - mechanical strength of the compressed mass increases - tendency of the compressed mass to disaggregate decreases

Question 29

what happens during compression

Answer 29

1. repacking of particles 2. elastic or plastic deformations 3. powder or granule fragmentation and formation of new surfaces 4. cohesion between particles 5. elastic or plastic deformation of the solid mass 6. tablet ejection

Question 30

advantages of uncoated tablets

Answer 30

they're cheap and easy to make

Question 31

advantages of coated tablets

Answer 31

easy to swallow

Question 32

what do effervescent tablets contain

Answer 32

bicarbonate and citrate to dissolve

Question 33

advantages of modified release tablets

Answer 33

they control how and at what rate disintegration occurs

Question 34

what are the types of tablet coatings

Answer 34

- sugar coating - film coating - press coating

Question 35

what are the steps to sugar coating

Answer 35

1. sealing of tablet cores 2. subcoating 3. smoothing 4. colouring 5. polishing 6. printing (optional step)

Question 36

advantages of film coating to sugar coating

Answer 36

1. less volume increase 2. better stability of the tablet 3. better mechanical strength 4. one step process

Question 37

what does coating suspension contain

Answer 37

1. polymer, ethers of cellulose, other polymers 2. plasticisers (PEG, oils) 3. colourants (iron exide etc) 4. solvents (used to be organic, now usually water)

Question 38

what is a gastro-resistant coating

Answer 38

a polymer coating that disintegrates/dissolves at a pre-determined trigger

Question 39

why would a gastro-resistant coating be used

Answer 39

some drugs dissolve too quickly in the stomach and patients can't actually get the drug

Question 40

advantages of gastro-resistant coating

Answer 40

1. protect stomach from drug (NSAIDS) 2. protect acid sensitive drugs

Question 41

how does gastro-resistant coating work

Answer 41

carboxylic acids at low pH are unionised, when pH increases they become ionised and being to dissolve

Question 42

why can't you crush gastro-resistant coating drugs

Answer 42

it removes the enteric coating and the drug will dissolve fully in the stomach

Question 43

challenges of gastro-resistant drug

Answer 43

the pH of the GI tract is not always predictable

Question 44

what is colonic targeting used for

Answer 44

to ensure drug breaks down in the colon

Question 45

how does colonic targeting coating work

Answer 45

bacteria in the gut breaks down the coating and allows the tablet to break down

Question 46

challenges in colonic targeting coating

Answer 46

if the patient has issues with their gut microbiome, the bacteria needed to break down the tablet may not be there

Question 47

examples of ingredients in colonic targeting coating

Answer 47

ethylcellulose, resistant starches