Drug Release Profiles Flashcards
Define Drug Release Profiles
graphical representation of the amount of drug released as a function of time
Why is drug release profile important?
Gives an indication of how the drug will perform in the body
What is burst phase?
Immediate release of drugs initially due to rapid dissolution and release of drug at the surface of the device
What is controlled release phase?
mechanism of release involves both diffusion of the drug through the polymer matrix and through degradation of the polymer
A drug eluting stent is an example of what type of system?
Diffusion controlled matrix system
Explain Matrix (monolithic) systems
- surrounding water enters and penetrates release units and dissolves drug
- diffusion takes place in pores
- burst effect - surface drug dissolved first and released rapidly
- the more drug dissolved, the larger the diffusion distance
Hydrogel is an example of what type of system?
Diffusion controlled - Matrix - polymer sweliing system
As opposed to matrix system, the diffusion distance of reservoir system is…
constant
Matrix system, drug diffuses through pore; for reservoir system, drug diffuses through…
thin water insoluble film or membrane
PDMS
polydimethylsiloxane
OROS
Osmotic Release Oral System
how does OROS tablet/capsule work?
water permeable membrane, as water enters, osmotic pressure pushes the active drug through the laser-drilled hole on the surface
