Pharmacology

Question 1

what are the main routes of drug administration in the skin?

Answer 1

topical
transdermal
subcutaemous
other epithelial routes (airways conjunctival sac, nasal mucosa and vagina)

Question 2

model of the stratum corneum

Answer 2

brick and mortar model

Question 3

three types of diffusion for drug delivery into the skin

Answer 3

intercellular
transcellular
transappendageal

Question 4

which vehicle contains the most water

Answer 4

lotions

Question 5

which vehicle contains the least water

Answer 5

powders

pastes

Question 6

describe lotion

Answer 6

suspension/solution of medication in water

Question 7

when can lotions sting?

Answer 7

if they contain alcohol

Question 8

what are lotions used to treat?

Answer 8

hair bearing areas such as the scalp

Question 9

describe creams

Answer 9

semisolid emulsion of oil in water, containing emulsifier and preservative

Question 10

what is good about creams

Answer 10

they are non-greasy so cosmetically acceptable

Question 11

describe ointments

Answer 11

semisolid grease that does no contain a preservatives

Question 12

what is bad about ointments?

Answer 12

they are less cosmetically acceptable

Question 13

describe gels

Answer 13

thickened aqueous solutions containing high molecules weight polymers e.g. methyl cellulose

Question 14

define pastes

Answer 14

semisolids finely powdered material (ZNO)

stiff, greasy and used in bandages

Question 15

describe foams

Answer 15

colloid with two or three phases

Question 16

five types of topical therapies

Answer 16

1. emollients
2. topical steroids
3. anti-infectives
4. antipruritic
5. keratolytic

Question 17

when are emollients used?

Answer 17

dry/scaly conditions

Question 18

appliance of emollients

Answer 18

300-500g per week
after bathing
in direction of hair growth

Question 19

role of topical steroids

Answer 19

vasoconstriction and antiinflammation

range from mild to very potent

Question 20

appliance of topical steroids

Answer 20

20-30g for whole body

Question 21

side effects of steroids

Answer 21

thinning of skin
purpura
rosacea
telangiectasia
systemic absorption (Cushing's)
tachyphylaxis

Question 22

three types of anti-infectives

Answer 22

antiseptics
antivirals
antifungals

Question 23

examples of antiseptics

Answer 23

iodine
hydrogen peroxide
triclosan
chlorhexidine

Question 24

examples of antifungals

Answer 24

nystatin
clotrimazole
ketoconazole

Question 25

examples of antipruritics

Answer 25

methanol
capsaicin
phenol
crotamiton

Question 26

role of keratolytic therapies

Answer 26

soften keratin

Question 27

when are keratolytics used

Answer 27

warts

Question 28

role of calcineurin inhibitors

Answer 28

suppress lymphocyte activation

Question 29

factors that increase partitioning into the skin

Answer 29

hydration of skin by occlusion

inclusion of excipients

Question 30

role of excipients

Answer 30

increase solubility of hydrophobic drugs

Question 31

factors that affect absorption

Answer 31

nature of the skin e.g. site, hydration and thickness

drug preparation e.g. concentration, sail and vehicle

Question 32

define the subcutaneous route of administration

Answer 32

needle into adipose tissue

Question 33

how does the drug delivered by subcutaneous route enter

Answer 33

enters systemic circulation via capillaries or lymphatic vessels

Question 34

benefit of subcutaneous route of administration

Answer 34

slow absorption

Question 35

disadvantage of subcutaneous route of administration

Answer 35

limited volume injected

Question 36

why is the skin a beneficial route for drug administration?

Answer 36

simple and non sterile
allows for steady-state plasma concentration
avoids first pass metabolism
drug absorption can be terminated rapidly

Question 37

disadvantage of the skin as a route for drug administration

Answer 37

only a limited number of drugs can diffuse across the epidermis

Question 38

describe transdermal drug delivery

Answer 38

drug is incorporated into an adhesive patch

Question 39

how does transdermal drug delivery increase permeability

Answer 39

enhancers interact with the lipid matrix