Pharmacology Flashcards
What are the 3 major route for medications?
Topical
Transdermal
Subcutaneous
What does the stratum corneum consist of?
Corneocytes and intracellular lipids
What is the structure of the stratum corneum like?
Bricks (corneocytes) and cement (intracellular lipids)
What substances does the stratum corneum allow to pass through it?
Small, hydrophobic
What does Fick’s Law calculate and what is the equation?
Rate of absorption
J = Kp Cv
In Fick’s Law what do these letter stand for ?
K
C
J
K = permeability coefficient C = concentration of the drug vehicle J = flux
What can improve partitioning?
Hydration of the skin
Inclusion of exipitents
What are the 4 categories of topical steroids?
Mild
Moderate
Potent
Very potent
What potency category is 1% Hyrdrocortisone acetate?
Mild
What two vessels do drugs given subcutaneously reach by diffusion?
Capilleries
Lymphatics
Disadvantage of giving drugs subcutaneously?
Injection volume limited
Advantages of giving drugs subcutaneously?
Absorption slow Route for many protein drugs e.g. insulin Route for oil bases drugs e.g. steroids Can give slow release over time simple painless
How are transdermal drugs applied?
Through adhesive patch placed on epidermis. Occurs through diffusion
What factor make certain drugs most suitable for transdermal appliance?
Low molecular weight
moderately lipophilic
potent
relatively short half life
Advantages of transdermal appliance?
Steady rate of drug delivery Decrease dosing frequency Avoidance of first pass metabolism Rapid termination User friendly Convenient and painless