Drug Delivery Systems Flashcards
What factors should be considered for drug delivery?
- Drug physico-chemical properties
- Body effects and interactions
- Improvement of drug effect
- Patient comfort and well being
Depends upon concentration achieved at the site
of action which depends on:
- Dosage
- Extent of absorption
- Distribution to the site
- Rate/extent of elimination
List conventional drug delivery systems
enteral
parenteral
other
List controlled drug delivery systems
sustained
extended
site-specific
pulsatile
List some barriers to protein drug delivery
enzymatic
intestinal epithelial
capillary endothelial
blood brain
Explain enzymatic barriers
limits absorption of protein drugs from GI tract
Explain intestinal epithelium barrier
involved in the transport of protein drugs across the intestinal epithelium
Explain blood brain barrier
involved in transport of protein drugs to brain compartment
List some approaches to enhance bioavailability of proteins
increase the permeabiliyt of absorption barrier
decrease pepitdase activity at the site of absorption and along the absorption route
Explain how to increase the permeability of absorption barrier
addition of fatty acids/phospholipids, bile salts and others
through iontophoresis
by using liposomes
Explain how to decrease peptidase activity at the site of absorption
protease inhibitors
enhance resistance against degradation by modification of the molecular structure
prolongation of exposure time
Explain iontophoresis
a transdermal electrical current is induced by positioning two electrodes on different places on the skin
Reasons why drugs fail
active compound never reaches the target
molecules do not enter cells
small fraction of drug reaches the site
What should be balanced when determining targeted drug therapy?
should maximize the therapeutic effect and avoid toxic effects elsewhere (few s/e)
Drug targeting is the concept where attempts are made to increase the therapeutic efficacy of drugs by…
specific delivery of the active compound at its site of action
to keep it there until it has been inactivated and detoxified