1 - TOPICAL CORTICOSTEROIDS Flashcards
(159 cards)
Topical corticosteroid potency relates to the intensity of the topical corticosteroid clinical effect
True
The Stoughton Vasoconstriction Assay correlates topical corticosteroid potency well with clinical efficacy and is reproducible
True (although it only measures one aspect of topical corticosteroid effects - vasoconstriction)
The resultant clinical potency of a TCS preparation depends on 4 interrelated factors:
(1) structure of the corticosteroid molecule
(2) the vehicle
(3) concentration of the corticosteroid molecule
(4) characteristics of the skin onto which the TCS is applied
True
Hydrocortisone (cortisol) is the backbone of most TCS molecules
True
The removal, replacement, or masking of hydroxyl groups changes a given molecule’s lipophilicity, solubility, percutaneous absorption and glucocorticoid receptor binding activity
True
Clobetasol propionate is a superpotent topical corticosteroid
True (clobetasol binds more tightly to the glucocorticoid receptor)
Moisturisers are incorporated into the vehicle to retard transepidermal water loss
True
Moisturisers are incorporated into the vehicle to occlude the corticosteroid molecule
True
Moisturisers are incorporated into the vehicle to increase the flexibility of the skin
True
Emulsifying agents in the vehicle are required to create oil-in-water preparations such as creams and lotions
True (help to distribute the TCS molecule evenly on the skin surface)
Solvents in the vehicle in lotions, solutions, gels, and sprays create a less viscous product
True
Humectants are necessary in oil-in-water preparations (vehicle) to maintain the required water content
True
Solvents such as propylene glycol and ethanol affect the TCS molecule’s solubility in the vehicle and skin by affecting its percutaneous absorption
True (the net effect of propylene glycol is to enhance potency through increasing the percutaneous absorption)
Very occlusive vehicles enhance a TCS’s molecule’s percutaneous absorption probably by increasing the hydration of the stratum corneum
True (thus a TCS molecule in an ointment vehicle tends to be more potent than the same concentration of the molecule in a cream or lotion)
Penetration of the applied TCS correlates inversely with the thickness of the stratum corneum
True (condition of the skin affects bioavailability)
Penetration of TCS increases with inflamed or diseased skin
True
Penetration of TCS increases with increased hydration of the stratum corneum
True
Penetration of TCS increases with relative humidity
True (hence WET dressings)
Penetration of TCS increases with temperature
True (hence wet dressings are soaked in LUKEWARM water)
The stratum corneum may act as a reservoir for TCS for up to 5 days
True (this retention is TCS concentration and formulation dependent)
The vehicle is a highly engineered balance of numerous chemicals (1) emollients, (2) emulsifying agents, (3) humectants, (4) emulsion stabilisers and viscosity builders, (5) thickening, stiffening and suspending agents, (6) solvents, (7) preservatives, antioxidants and chemical stabilisers
True
Petrolatum is an occlusive moisturiser
True
Glycerin is a humectant moisturiser and solvent
True
Propylene glycol is a humectant moisturiser, solvent, and functions as a preservative, antioxidant and chemical stabiliser
True