Pharmaceutics: Exicipients For Powder Mixtureso

Question 1

What is an excipient?

Answer 1

an inactive substance that serves as the vehicle or medium for a drug or other active substance.

Question 2

What makes an ideal excipient?

Answer 2

1) Inert - doesn’t react with drug or other excipients
2) Safe - non-toxic, non-allergenic, non-irritant
3) Quality Assured - appropriate purity/grade, performs the same across batch, complies with quality standards.
4) Economical

Question 3

6 types of excipients?

Answer 3

1) diluent - bulk up the volume
2) binder - makes particles stick
3) disintegrant - disperses particles when in contact with water
4) glidant - helps particles flow past each other
5) anti-adherent - reduce adhesion between stationary powder and equpiment.
6) lubricant - reduce sticking of powder/tablet to equipment

Question 4

6 common excipients used?

Answer 4

1) Lactose
2) Starch
3) Cellulose
4) Talc
5) Colloidal silicon dioxide
6) Magnesium Stearate

Question 5

What is Lactose and where is it found?

Answer 5

• Lactose is a sugar found in milk.
• disaccharide of glucose and galactose.
• undergoes the Maillard reaction to produce a yellow-brown colour by reacting with primary amines. So is considered a reducing sugar.

Question 6

Is lactose water soluble?

Answer 6

yes

Question 7

problem with using lactose as an excipient?

Answer 7

problematic for lactose-intolerant individuals.

Question 8

What does it mean when Lactose is GRAS-listed?

Answer 8

It is Generally Regarded As Safe to use!

Question 9

What type of excipient is lactose monohydrate?

Answer 9

• for tablets and capsules it is a diluent.

- in wet granulation tableting it is a binder.ww

Question 10

What type of excipient is anhydrous lactose?

Answer 10

Used as a diluent and binder for hard-shell capsules and direct-compression tablets.

Question 11

Which of the lactose isomers exist more when it’s anyhydrous?

Answer 11

beta-lactose (70-80%)
alpha-lactose (20-30%)
so beta exists more.

Question 12

What type of excipient is spray-dried lactose?

Answer 12

diluent and binder in direct compression tableting.

Question 13

Although starch is GRAS-listed, there are still downsides to using it such as?

Answer 13

wheat proteins (gluten) - problematic for celiac disease

Question 14

Which of the two is generally more in natural starch, amylose or amylopectin?

Answer 14

Amylopectin

Question 15

What type of excipient is natural starch used as?

Answer 15

• binder
• diluent
• disintegrant
• anti-adherent
• lubricant

(basically all except glidant)

Question 16

What type of excipient is pregelatinised starch used as?

Answer 16

• binder (better than natural starch)
• diluent
• disintegrant

(used in wet and dry granulation and in direct-compression in tableting)

Question 17

What is cellulose made of?

Answer 17

D-glucose (beta-glucose)

Question 18

Where is cellulose found?

Answer 18

In the pulp of fibrous plants

Question 19

What type of excipient is powdered cellulose used as?

Answer 19

• binder - for hard-shell capsules
• diluent - in tablets
• disintegrant - in tablets
• glidant - in tablets

Question 20

What type of excipient is microcrystalline cellulose used as?

Answer 20

• binder and diluent - in wet granulation and direct-compression in tableting.
• disintegrant
• anti-adherent
• lubricant
• adsorbent

Question 21

Problems with using Talc as an excipient?

Answer 21

1) may contain traces of aluminium silicate and iron making it incompatible with quaternary ammonium compounds.
2) purity varies with geographical source and may need purifying (timely and costly
3) may contain asbestos which is a carcinogenic

Question 22

What type of excipient is talc used as?

Answer 22

• glidant
• lubricant
• anti-adherent
• adsorbent
• dissolution retardant

Question 23

Why is talc coated on larger particles?

Answer 23

to reduce cohesion. adhesion and friction

Question 24

Is colloidal silicon dioxide soluble in water?

Answer 24

nope, it forms a colloidal dispersion in water

Question 25

What type of excipient is colloidal silicon dioxide used as?

Answer 25

• glidant
• tablet disintegrant
• adsorbent

Question 26

What type of excipient is Magnesium stearate used as?

Answer 26

-lubricant

Question 27

What three things is magnesium stearate insoluble in?

Answer 27

ethanol, water and ether

Question 28

How does magnesium stearate accelerate aspirin degradation?

Answer 28

increases aspirin solubility and hydrolysis by elevating the pH.

Question 29

What three things is magnesium stearate incompatible with?

Answer 29

1) strong oxidising agents
2) Iron salts
3) strong acids and alkalis.