Creams, Ointments And Other Topical Flashcards
What does topical mean
Applied to any external body surface for a localised effect
Why do we give treatment locally to the skin
Enhance barrier function of the skin
Targeted delivery to specific layers of the skin
Topical formulation to treat the skin has fewer side effects compared to oral delivery
Examples of formulations that improve skin barrier function
Sunscreen protect against uv radiation
Antibiotics against infection
Emollients for dry skin conditions
Moisturisers
Barrier creams to prevent exposure of skin to harsh chemicals
Where do you apply sunscreen/insect repellent (scientifically)
Above or on the stratum corneum for easier target
What does occlusive mean
The formulation prevents water movement out of the body
Occlusive preparation increases skin hydration and moisture content
Two types of soft paraffin
Yellow petrolatum Vaseline
White petrolatum
Properties of hydrocarbon ointments
Occlusive
Emollient= hydrate skin due to moisture accumulation
Skin hydration keeps skin supple
Difficult to remove
Greasy
Good if drug not stable in water
Two types of ointments
Hydrocarbons
Water soluble ointments
Properties of water soluble ointments
Water soluble
Washable
Non greasy
Non occlusive
Why are creams popular for topical application
Good delivery system for many drugs
Good patient acceptability
Spread easily
Not as occlusive as ointments
For o/w creams, water evaporates to leave a thin film on the skin
How are calcium soaps produced
Mixing fatty acid with lime water to form calcium hydroxide solution to ford a soap. They are used to form w/o emulsion
Transdermal delivery
Aims to get drug into bloodstream
Avoids problems associated with oral delivery
Limitations of transdermal patches or gels
Skin is good barrier and large amounts of drug cannot permeate
Max daily dose
Max attainabke flux across skin
Influenced by drug properties
Examples of topical formulation
Ointments
Paste
Creams
Lotions
Liniments (lotion with oils)
Powder
Tincture/paint
Gels
Gelling agents
Carbomer gels
Topical patches
Collodions (sticky liquid which dries to a film)
