Excipients for Powder Mixtures

Question 1

What excipients are used for delivery?

Answer 1

Solvent
Co-solvent
Disintegrant

Question 2

What excipients are used for acceptability?

Answer 2

Colour
Falvourant

Question 3

What excipients are used for stability?

Answer 3

Antioxidant
Preservative
Suspending agents

Question 4

What excipients are used for handling (+ vol)?

Answer 4

Filer/diluent
Glidant
Lubricant

Question 5

What must excipient properties be?

Answer 5

Inert
Safe (non-toxic)
Economical
Quality–assured

Question 6

What are the excipients for powder mixtures?

Answer 6

Diluent
Binder
Disintegrant
Glidant
Anti-adherent
Lubricant

Question 7

What are the most common excipients?

Answer 7

Lactose
Starch
Cellulose
Talc
Colloidal silicon dioxide
Magnesium stearate

Question 8

What are the different types of lactose?

Answer 8

Monohydrate
Anhydrous
Spray-dried

Question 9

What are the different types of starch?

Answer 9

Natural
Pre-gelatinised

Question 10

What are the different types of cellulose?

Answer 10

Powdered
Microcrystalline

Question 11

Describe lactose

Answer 11

H2O soluble
Less sweet than sucrose

Question 12

What are the 2 isomers of lactose?

Answer 12

α-lactose
β-lactose.

Question 13

What are the problems with lactose?

Answer 13

Instability with primary amine-containing drugs.
Problematic for lactose-intolerant individuals.

Question 14

Describe lactose monohydrate

Answer 14

H2O content higher than lactose
Odourless
White

Question 15

How is lactose monohydrate formed?

Answer 15

Crystallised from supersaturated lactose solutions
Crystal shapes depend on method of precipitation

Question 16

What is lactose monohydrate widely used as?

Answer 16

Binder with wet granulation in tabletting
OR
Binder for tablets + capsules

Question 17

What do you not use lactose monohydrate with?

Answer 17

Drugs susceptible to hydrolysis

Question 18

How is anhydrous lactose produced?

Answer 18

Drying lactose solution, followed by milling + sieving

Question 19

What is anhydrous lactose used as?

Answer 19

Diluent + binder for tablets + hard-shell capsules

Question 20

What is anhydrous lactose suitable for?

Answer 20

Moisture-sensitive drugs.

Question 21

Describe spray-dried lactose

Answer 21

Mixture of α-lactose monohydrate and amorphous lactose

Question 22

How is spray-dried lactose produced?

Answer 22

Spray-drying lactose solution

Question 23

Why is it good that spray-dried lactose has spherical particles?

Answer 23

High compactability

Question 24

What is spray-dried lactose primarily used as?

Answer 24

Diluent and binder in direct compression tableting.

Question 25

Describe starch

Answer 25

Extracted from food crops Amylose + amylopectin

Question 26

What is problem with starch?

Answer 26

Celiac disease

Question 27

Describe natural starch

Answer 27

Polysaccharide of D-glucose α-1,4-glycosidic bonds More amylopectin (branched) than amylose

Question 28

What is natural starch primarily used as?

Answer 28

Binder, diluent + disintegrant

Question 29

Describe natural starch powder

Answer 29

Odourless, tasteless, white, fine powder

Question 30

How is pregelantised starch formed?

Answer 30

Granules ruptured chemically at mechanically at 62-72°C

Question 31

Describe pregelatinised starch

Answer 31

Odourless, white powder with slight characteristic taste

Question 32

What is pregelatinised starch used as?

Answer 32

Binder, diluent + disintegrant

Question 33

What is better about pregelatinised starch than natural?

Answer 33

Improved binder properties

Question 34

Describe cellulose

Answer 34

Polysaccharide of D-glucose linked with β-1,4-glycosidic bonds Obtained from pulp of fibrous plants

Question 35

How is powdered cellulose obtained?

Answer 35

Obtained by mechanical particle size reduction of pulp

Question 36

Describe powdered cellulose

Answer 36

White, odourless, tasteless Slightly hygroscopic

Question 37

What is special about powdered cellulose?

Answer 37

Wide range of particle sizes ranging from fine to coarse, free flowing to non-flowing, dense or fluffy

Question 38

What is powdered cellulose primarily used as?

Answer 38

Diluent for hard-shell capsules

Question 39

Describe microcrystalline cellulose

Answer 39

Porous, hygroscopic, crystalline White, odourless, tasteless

Question 40

How is microcrystalline cellulose obtained?

Answer 40

Through controlled acid-hydrolysis and spray-dried

Question 41

What is microcrystalline cellulose primarily used as?

Answer 41

Diluent + binder in wet granulation + direct compression

Question 42

Describe talc

Answer 42

Hydrous magnesium silicate May contain traces of aluminium silicate and iron

Question 43

How is talc obtained?

Answer 43

Mineral—mined, pulverised and purified

Question 44

What must talc be free from?

Answer 44

Asbestos (carcinogenic) Iron

Question 45

What is talc primarily used as?

Answer 45

Glidant, anti-adherent + lubricant

Question 46

What does talc do?

Answer 46

Coats larger particles to reduce cohesion, adhesion and friction

Question 47

What is talc insoluble in?

Answer 47

Dilute acids and alkalis, organic solvents and water

Question 48

What is asbestos-free talc considered?

Answer 48

Non-toxic, not absorbed orally

Question 49

What is talc incompatible with?

Answer 49

Quaternary ammonium compounds

Question 50

Describe colloidal silicon dioxide

Answer 50

Odourless, tasteless, white/bluish-white powder

Question 51

What is colloidal silicon dioxide insoluble in?

Answer 51

Practically H2O and organic solvents

Question 52

What does colloidal silicon dioxide form in H2O?

Answer 52

Forms colloidal dispersion

Question 53

What is colloidal silicon dioxide used as?

Answer 53

Glidant = coats larger particles to reduce cohesion

Question 54

How is colloidal silica dioxide formed?

Answer 54

Prepared by flame pyrolysis of chlorosilanes in hydrogen-oxygen flame at 1800°C, then cooled rapidly

Question 55

Describe magnesium stearate

Answer 55

Greasy to the touch, cohesive and adherent Faint odour and taste of stearic acid Hydrophobic

Question 56

What is magnesium stearate practically insoluble in?

Answer 56

Ethanol, ether + water

Question 57

What is magnesium stearate incompatible with?

Answer 57

Strong oxidising agents

Question 58

What can magnesium stearate cause?

Answer 58

Aspirin degradation = increases solubility + hydrolysis by elevating pH

Question 59

What is magnesium stearate primarily used as?

Answer 59

Lubricant