4_2TopTransderm1

Question 1

What is the most common disease of the skin?

Answer 1

infection

Question 2

What are the 3 general purposes of drug delivery to the skin?

Answer 2

1) surface delivery, 2) local delivery, 3) transdermal/systemic delivery

Question 3

What drug classes are administered for surface delivery?

Answer 3

cleansers and protectives

Question 4

What drug classes are administed for local delivery?

Answer 4

protectives, keratolytics, anti-inflammatories

Question 5

Why are drugs administered transdermally?

Answer 5

1) to avoid side effects, 2) avoid first pass, 3) prolonged release

Question 6

What are the functions of skin?

Answer 6

1) barrier; 2) fluid containment; 3) stimulus reception; 4) temp regulation; 5) synthesis/metabolism; 6) waste disposal

Question 7

What are the layers of the skin?

Answer 7

epidermis, dermis, subq

Question 8

thickness of epidermis

Answer 8

100 um

Question 9

thickness of dermis

Answer 9

2-3mm

Question 10

What are the general layers of the epidermis?

Answer 10

stratum corneum + stratum germanitivum

Question 11

What is the barrier to drug transport thru the skin?

Answer 11

strateum corneum

Question 12

What is the turnover length of the stratum corneum

Answer 12

2 weeks

Question 13

Describe the general composition of the sc?

Answer 13

5% membrane lipids; 85% cell contents; 10% intracellular membrane lipids

Question 14

Describe the intracellular contents in the sc?

Answer 14

50% alpha-keratin, 20% beta-keratin, 20% lipids, 10% protein

Question 15

stratum corneum thickness in back

Answer 15

10 um

Question 16

stratum corneum thickness in abdomen

Answer 16

15 um

Question 17

stratum corneum thickness in forearm

Answer 17

16 um

Question 18

What % of skin surface are do appendages make up?

Answer 18

0.10%

Question 19

What is the density of hair shaft on the skin?

Answer 19

40-70 cm2

Question 20

What is the density of sweat glands on the skin?

Answer 20

200-250 glands/cm2

Question 21

What are the two pathways of drug transport through the skin?

Answer 21

trans-epidermal and trans-follicular

Question 22

Describe the contents of the dermis

Answer 22

capillaries, nerves, lymph, sebaceous glands

Question 23

Describe the contents of SQ tissue.

Answer 23

adipose and collagen with eccrine sweat glands, vasculature, and hair bulb

Question 24

What are the bricks in the brick and mortar model?

Answer 24

keratinized cells

Question 25

What is the mortar in the brick and mortar model?

Answer 25

extracellular lipids

Question 26

Describe the required drug solubility in different mediums to cross via the intracellular route?

Answer 26

soluble in hydrophilic protein core and soluble in extracellular lipid

Question 27

Describe the required drug solubility in different mediums to cross via the intercellular route.

Answer 27

must be soluble in extracellular lipid

Question 28

How does the intercellular pathway differ from the intracellular pathway?

Answer 28

torturous pathway if inter- is 50 times longer

Question 29

Describe the total flux or drug transport through the skin.

Answer 29

sum of the trans-epidermal pathway and the trans-follicular pathway

Question 30

What things have an effect on drug absorption?

Answer 30

1) drug properties, 2) vehicle properties, 3) pathway of permeation

Question 31

What is the slope of a plot of amount penetrated vs time?

Answer 31

flux

Question 32

What equipment is used to measure flux through a skin sample?

Answer 32

1) franz diffusion cell; 2) keshary-chen diffusion cell

Question 33

On what factors is lag time highly dependent?

Answer 33

thickness and diffusivity

Question 34

Lipinskis rules of 5 for ORAL

Answer 34

1) mw - 500
2) log K - 5
3) H donors - 5
4) H acceptors - 10

Question 35

Lipinskis rules of 5 for transdermal

Answer 35

1) mw - 335
2) log K - 5
3) H donors - 2
4) H accept - 5