Pharmacology

Question 1

What are.. the main routes of drug administration through the skin?

Answer 1

Topical
Transdermal
Subcutaneous

Question 2

What is topical administration?

Answer 2

Applying the drug to the surface of the skin

Question 3

What are two ways that drugs can penetrate the keratin layer?

Answer 3

Through the cells (Transcellular) or between them (intercellular)

Question 4

What route do drugs usually move through the stratum corneum?

Answer 4

Intercellular

Question 5

When are topical skin therapeutics used?

Answer 5

Superficial skin disorders
-Psoriasis
-Eczema
Skin infections
Itching
Dry skin
Warts

Question 6

What is a vehicle?

Answer 6

A substance a drug is suspended in

Question 7

What is the purpose of a vehicle?

Answer 7

Get to the site of action quicker

Increase the concentration of a drug at that site

Question 8

List some vehilcles

Answer 8

Tesla 
Ointments
Creams
Gels
Lotions
Pastes
Powders

Question 9

Does the vehicle have a large effect on the rate and extent of absorption of the drug?

Answer 9

Yes

Question 10

Where does the drug need to dissolve better, the vehicle or the skin?

Answer 10

The skin

Question 11

What is transdermal drug delivery?

Answer 11

A passive process driven by diffusion

Question 12

What is ficks law of diffusion?

Answer 12

Rate of absorption = Kp x Concentration of drug in vehicle

Question 13

What can enhance solubility and absorption of a drug?

Answer 13

Addition of excipients

Question 14

Are topical drugs absorbed well?

Answer 14

No

Question 15

What factors affect the absorption of a topical drug?

Answer 15

Hydration of the skin
Inclusion of excipients
Barrier funciton
Nature of skin
Site of application
Integrity of epidermis
Drug preperation
Vehicle

Question 16

How do glucocorticoids signal?

Answer 16

Via nuclear receptors (class 1)

Question 17

Are glucocorticoids lipophillic or lipophobic?

Answer 17

Lipophilic

Question 18

How do glucocorticoids enter the cell?

Answer 18

Diffusion across the plasma membrane

Question 19

What do glucocorticoids bind to within the cytoplasm?

Answer 19

GRa

Question 20

What does the binding of GCs to GRa cause?

Answer 20

Dissociation of inhibitory heat shock proteins

Question 21

What happens to the activated GRa receptor?

Answer 21

Translocates into the nucleus

Question 22

What aids translocation of GRa receptor into the nucleus?

Answer 22

Importins

Question 23

What do activated receptors assemble into in the nucleus?

Answer 23

Homodimers

Question 24

What do homodimers bond to?

Answer 24

Glucocorticoid response elements (GRE) in the promoter region of specific genes

Question 25

What is the outcome of the homodimers binding to GREs?

Answer 25

Transrepression

Transactivation

Question 26

What is subcutaneous administration?

Answer 26

When a drug is delivered by a needle into the fatty tissue just beneath the surface of the skin

Question 27

How does a subcutaneous drug reach systemic circulation?

Answer 27

Diffusion into the capillaries or lymphatics

Question 28

What are the negatives to subcutaneous administation?

Answer 28

Slow absorption
Mainly for protein and oil based drugs
Injection volume limited
Pain?

Question 29

What makes the skin a good site for drug administration?

Answer 29

Application is simple and non-sterile
Steady-state plasma concentration
Avoids first pass metabolism
Drug absorption can be terminated rapidly

Question 30

What is transdermal drug delivery?

Answer 30

Drug is incorporated into an adhesive patch

Question 31

How is transdermal drug delivery partially controlled?

Answer 31

Drug release

Question 32

What type of drug is transdermal delivery most suitable for?

Answer 32

LMW drugs
Moderately lipophillic
Potent
Relatively brief half life