skin formulations

Question 1

what is the advantage to using skin formulations

Answer 1

can be applied directly to diseased tissue

Question 2

what is the disadvantage to using skin formulations

Answer 2

skin is designed to be a highly effective barrier- prevent drug entry

Question 3

what are topical formulations used for

Answer 3

localised action Reach systemic circulation at sub-therapeutic levels

Question 4

what are transdermal formulations used for

Answer 4

External Skin is not primary target Drugs transport through percutaneous route to systemic circulation

Question 5

what are some examples of skin formulations

Answer 5

solutions collodion suspensions emulsions

Question 6

what is the role of emollients

Answer 6

to rehydrate the skin

Question 7

what is the role of barrier creams

Answer 7

protect skin from irritants

Question 8

how is ciclosporin cream formulated

Answer 8

W/O

Question 9

how are NSAID creams formulated

Answer 9

O/W

Question 10

what are the four types of ointments

Answer 10

hydrophobic fats/oils emulsifying water soluble

Question 11

what are the 5 dermatological target regions

Answer 11

surface stratum corneum skin appendages viable epidermis-dermis systemic

Question 12

how does transdermal delivery work

Answer 12

Released drug at rate below maximal rate for controlled systemic therapy

Question 13

what are the two routes transdermal absorption

Answer 13

Transcellular: through the keratinocytes Intercellular: around keratinocytes via small gaps

Question 14

what are the advantages of transdermal drug delivery

Answer 14

• Avoids first pass metabolism in liver- Consistent site of absorption - Constant drug input rate - Can stop by removing patch

Question 15

what are some examples of drugs that are delivered transdermally

Answer 15

• Scopolamine : travel sickness - GTN : angina - Estradiol : HRT - Contraceptives

Question 16

how are drug candidates decided for transdermal delivery

Answer 16

high potency - only small amount passes through timescale of exposure site/skin condition formulation skin barrier alteration skin hydration

Question 17

how does skin hydration affect transdermal drug delivery

Answer 17

hydrated skin is more permeable

Question 18

name 3 drugs formulated for skin that are currently used

Answer 18

glucocorticoids retinoids vitamin d analogues

Question 19

how do glucocorticoids work topically/transdermally

Answer 19

inhibit release of inflammatory mediators (NFkB), neutrophils activation and mast cell release

Question 20

what is an example of a mild steroid cream

Answer 20

hydrocortisone

Question 21

what is an example of a moderate steroid cream

Answer 21

clobetasone

Question 22

what is an example of a potent steroid cream

Answer 22

betamethasone

Question 23

what is an example of a very potent steroid cream

Answer 23

clobetasol

Question 24

what are some side effects of prolonged topical steroid use

Answer 24

rebound atrophy infection rosacea

Question 25

how do retinoids work topically/transdermally

Answer 25

bind to RXR/RAR nuclear receptors in keratinocytes/sebaceous glands to decrease proliferation and sebum production

Question 26

side effects of retinoids

Answer 26

dry skin stinging joint pains teratogenic

Question 27

how do vitamin d analogues work topically/transdermally

Answer 27

○ Act via VDR to modulate gene transcription in keratinocytes, fibroblasts, langerhans cells and sebaceous glands ○ Inhibit T cell activation

Question 28

what is the main side effect for topical/transdermal vitamin d analogues

Answer 28

skin irritation