5. Pastes

Question 1

What are pastes?

Answer 1

The semi solid stiff preparation containing higher proportion of finally powdered intended for application to the skin.

Question 2

What are the uses of pastes?

Answer 2

The principle use of pastes is antiseptics , protective and soothing effect and often before application the paste is applied to lint and applied as dressing.

Question 3

What are the types of bases used in pastes?

Answer 3

1. Hydrocarbon base
2. Water miscible base
3. Water soluble base

Question 4

Hydrocarbon base

Answer 4

soft paraffin is used in Compound Zinc Paste B.P
liquid paraffin used in Compound Aluminium Paste B.P.C

Question 5

Water miscible base

Answer 5

Emulsifying wax used in zinc and coal tar paste B.P.C
Emulsifying ointment is used as base in Resorcinol and Sulphur paste B.P

Question 6

Water soluble base

Answer 6

macrogol bases used in dental pastes
These bases are also used in Triamcinolone Dental Pastes

Question 7

What are the advantages of pastes?

Answer 7

1. Stiffer than other semi-solids so remain stable at the site of application
2. Do not interfere with healthy area of body
3. Considerably less greasy than ointments
4. Have more ability to absorb wound exudate
5. It is used in nappy products because it absorbs ammonia gas produce by bacterial action on urine

Question 8

What are the disadvantages of pastes?

Answer 8

1. Proper device is required for application because they are first applied on lint and then applied as dressing
2. Medicament of larger size will not be easy to spread and remain localized
3. Need to apply on moist area
4. Difficult to remove from hairy area

Question 9

What are the methods of preparation of paste?

Answer 9

When vehicle is liquid then only fusion method is used
When base is semi solid then fusion or trituration is used

Question 10

Give formulation of Lassar paste

Answer 10

Zinc oxide 240g
Salicylic acid 20g
Starch 240g
White soft paraffin 500g

Question 11

Give uses of Lassar paste

Answer 11

For treatment of diapper rashes.
For healing of Cracked Heals
For hyperkeratosis (abnormal thickening of outer layer of skin)

Question 12

Give the method of preparation with Lassar paste

Answer 12

1. Sieve the zinc oxide and salicylic acid through 180 sieve before weighing.
2. Weight the soft paraffin and melt in evaporating basin on a water bath
3. Take some of the mixture of zinc oxide and salicylic acid and stir into the melted base
4. Continuously all the above ingredients are added and stir gently until cold
5. Weight out the lassar paste

Question 13

How are pastes packaged?

Answer 13

Pastes are generally packed in wide mouth jars or collapsible tubes protected from light

Question 14

How are pastes stored?

Answer 14

Should be stored at cool place

Question 15

Which labels are used on pastes?

Answer 15

‘’For External Use Only’’ must be mentioned
Discard date usually three months