Pharmacology

Question 1

Routes of drug administration in dermatology

Answer 1

Topical
Transdermal
Subcutaneous

Question 2

The _____ layer is the most important barrier to drug penetration into the skin or diffusion across it

Answer 2

Keratin

Question 3

Keratin layer is lipophilic/lipophobic

Answer 3

Lipophilic

Question 4

Routes of diffusion across the keratin layer

Answer 4

Intercellular (main route)
Transcellular
Trans-appendageal (via hair follicles and sweat glands)

Question 5

What are vehicles/bases?

Answer 5

Pharmacologically inactive substances that “carry” the drug

Question 6

Examples of vehicles

Answer 6

Powders
Pastes
Gels
Ointments
Creams
Lotions
Foams

Question 7

Rate of absorption follows ____ law of diffusion

Answer 7

Fick’s

J = Kp x Cv

Question 8

What is Kp in Fick’s law of diffusion?

Answer 8

Permeability coefficient (the movement of the drug from the vehicle into the keratin layer and beyond)

Question 9

What is Cv in Fick’s law of diffusion?

Answer 9

Concentration of drug in vehicle/concentration gradient across the barrier

Question 10

Mild steroid

Answer 10

Hydrocortisone 1%

Question 11

Moderate steroid

Answer 11

Modrasone clobetasone butyrate 0.05%

Betamethasone valerate 0.025%

Question 12

Potent steroid

Answer 12

Mometasome betamethasone

valerate 0.1%

Question 13

Very potent steroid

Answer 13

Clobetasol proprionate 0.05%