WEEK 6 Flashcards
What are the 4 types of bases used in ointments?
Hydrocarbon bases
Absorption bases
Water-miscible bases
Water-soluble bases
T or F
Ointments with hydrocarbon bases are not absorbed by the skin
T
T or F
Hydrocarbon bases are easier to apply/spread than absorption bases.
F
Name the 2 types of absorption bases
Non-emulsified and emulsified
What ingredient distinguishes non-emulsified ointments to emulsified ointments?
Emulsified ointments have water in them, whereas non-emulsified ointments do not.
T or F
Water-miscible bases are classified into five categories based on the surfactant they contain
F
three categories
Why are water-miscible ointments easier to wash off than absorption bases?
Whilst water-miscible ointments don’t contain any water, their emulsifying nature enables them to mix readily with aqueous secretions of the skin and be easier to wash off.
Name the 3 types of water-miscible base ointments
Anionic, cationic and non-ionic surfactants
Which type of water-miscible base ointment is compatible with most medications?
non-ionic surfactants
T or F
Creams are more emollient and less occlusive than ointments.
T
T or F
The main difference between creams and ointments is the amount of water.
T
What are the 2 main types of creams?
Oil-in-water (O/W) emulsions (aqueous creams) and water-in-oil (W/O) emulsions (oily creams)
Which type of cream is preferred for oral liquid emulsions?
Oil-in-water because the water phase is much more pleasant to taste than the oil phase
T or F
(regarding creams)
The ratio of the two phases (oil and water) indicates the type of emulsion.
F
the oil phase can be a higher percentage than the water phase in both O/W and W/O creams.
T or F
The emulsifying agent in oily creams are oil soluble
T
What does “thixotropic” mean?
Something that displays the properties of solids when left alone but displays the properties of liquids on agitation (e.g. gels)
What are the two types of gels?
Hydrogels and organogels
T or F
Pharmaceutical pastes are usually an ointment base with a small proportion of solids
F
large proportion of solids (50%+)
T or F
Pastes are not suitable in moist environments
F
They stay in place even in moist environments
What is the main difference between ointments and pastes?
a large proportion of solid material
What is viscosity?
A measure of a fluids resistance to flow
What is the official unit for force per unit area according to the international system of units (SI)?
the pascal (Pa)
What type of viscosity are people referring to when they mention the viscosity of a fluid?
Dynamic viscosity
