semi solid, drug disolved in greasy base, minimises water loss, difficlut to spread and low patient acceptabilty
2 of 20
describe creams
semi solid emulsion, long residence time, good mixing with skin, good acceptability
3 of 20
describe gels,
semi solid liquid, drug dissolved/ disperesed in liquid, film on skin
4 of 20
describe lotions
water based solution suspension or emulsion, high spreadability, good on hairy areas, short residence time
5 of 20
describe foams
dipsersion of gas in liquid, drug disolevde/disperesed in liquid, momentarily stbale as a foam
6 of 20
describe sprays
aerosal- liquid droplets dispersed in gas.rapid even large sa coverage
7 of 20
describe a patch
solid dose on advsie tape, good residence time and protection from envirnments
8 of 20
what are the advantages of topical
no 1st pass so smaller dose so less side effects. no gi degradation. easy to withdraw dose
9 of 20
what are disadvantages of topical
skin irrataion and low skin permability
10 of 20
what are the three skin layers
epidermis, dermis and hypodermis
11 of 20
what is permaibilty barrier describe it
stratum corneum on epidermis. dead cells with hard keratin envelope, encased in lipids. corneocytes as hydrophillic cells of stratum corneum
12 of 20
describe stratum corneum transport systems
transcellular-through corenocytes or paracellular -around lipid matrix
13 of 20
other transport pathways
shunt- in hair follicles or glands
14 of 20
describe drug properties effecting transport
lipophillics and molecular weight. linked by Kp
15 of 20
anatomical factors effecting drug abs
no. of follicles, skin thickness
16 of 20
age factors effecting abs
skin thickness, hydration, corneocytes get bigger with age
17 of 20
disease factors effecting drug abs
broken skin
18 of 20
two ways of assessing drug abs describe
1. tape *********-adhesive tape on stratum corneum to remove layrs and analyse drug level. 2. diffusion cells- skin smaple between donor and receptor chmabers. drug placed in donor. fluid in receptor end analysed for drug content
19 of 20
what in vitro skin models are there
human-best, cadavers, howevre consent and ethics. animal-pig-unethical. artical- made to match human skin permability, ethical and cheap
20 of 20
Other cards in this set
Card 2
Front
describe ointments
Back
semi solid, drug disolved in greasy base, minimises water loss, difficlut to spread and low patient acceptabilty
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