ch2 pt2

Question 1

Advantages of Theobroma oil (Cocoa butter)

Answer 1

1- melts at body temperature
2- Miscible with many ingredients
3- Non-irritating

Question 2

Disadvantages of Theobroma oil (Cocoa butter)

Answer 2

1- Polymorphism
2- Adherence to the mold
3- Melting point reduced by soluble ingredients
4. Rancidity on storage
5. Poor water-absorbing ability:
6. Leakage from the body
7. Expensive

Question 3

Advantages of Synthetic hard fat: e.g., witepsol

Answer 3

1- resistance to oxidation
2- No mold lubricant is necessary
3- water-absorbing capacities are good.

Question 4

Disadvantages of Synthetic hard fat: e.g., witepsol

Answer 4

1- Brittle if cooled rapidly, avoid refrigeration during preparation.
2- less viscous than Theobroma oil

Question 5

Disadvantages of Water soluble and water miscible bases.
A- Gylcero-gelatin

Answer 5

1- laxative effect
2- rectal irritation
3- Unpredictable dissolution time.
4- Hygroscopic
5- Microbial contamination
6- Long preparation time
7- Lubrication of the mold is essential.

Question 6

B- Macrogols (polyethylene glycols)
Advantages

Answer 6

a.No laxative effect.
b.Less microbial contamination
c. no lubricant is necessary
d. Suitable for hot climates
e. sustained effect
f. Produce high-viscosity solutions,so leakage is less likely

Question 7

B- Macrogols (polyethylene glycols)
Disadvantages

Answer 7

1- Hygroscopic
2- Poor bioavailability of medicaments
3- Incompatibilities
4- Brittleness

Question 8

C- Soap glycerin
Advantages

Answer 8

hard for suppositories
Soap assists the laxative action of glycerin, whereas
gelatin does not.

Question 9

C- Soap glycerin
Disadvantages

Answer 9

Very hygroscopic & require to be wrapped in wax paper
or pure tin foil & protected from the atmosphere

Question 10

Preparation of suppositories

Answer 10

1- Hand Molding
2- Compression Molding

Question 11

Problems in suppository formulation:

Answer 11

1- Water in suppositories
(oxidation, crystallization, excipient interactions, Bacterial contamination)

2- Hygroscopicity:
(high length of the molecule = low hygro)

3- Drug-excipient interactions

4- Viscosity:
(2% aluminum monostearate to increase viscosity of the base)

5- Brittleness:
(This problem can be overcome by keeping the temperature difference between the melted base and he mold as small as possible)

6- Lubrication of moulds:
(mineral oil, aqueous solution)

7- Rancidity:

8- Volume contraction:
(This can be minimized by pouring the suppository mass slightly above its congealing temperature into a mold warmed to about the same temperature.)
(Another way to overcome this problem is to overfill the molds and scrape off the excess mass which contains the contraction hole)

Question 12

Evaluation of suppositories

Answer 12

1- Appearance
II-Weight variation test
III- Breaking test
IV- Melting range test
V- Drug content estimation
VI- In-vitro drug release study
VII- Stability study