316 Q7

ndifranco94's version from 2015-09-17 19:22


Question Answer
Components of drug delivery devicedrug, device (e.g. polymer)
Diffusion releasenon-linear, dependent on THICKNESS, POLYMER CHARACTERISTICS, etc...
2 Forms of diffusion release drug delivery systemsMembrane bound reservoir, Monolithic device
Membrane bound reservoirfree drug inside semipermeable membrane, ZERO order release, high cost
Monolithic devicematrix bound drug, lower cost, release rate DECREASES WITH TIME
Zero order release-d[A]/dt = k, INDEPENDENT of starting conc
First Order release-d[A]/dt = k[A], DEPENDS on starting conc
Fick's First LawJ = -D(dc/dx)
Cumulative release curve can nevergo down
Problem w/ first order releaseBurst release could be dangerous if not needed
Burst releaselarge release at first, slows over time
When is burst useful?cancer, bacterial infection, diabetes
Diffusion equation w/ elimination
Danger of membrane bound reservoirsif membrane fails, release all drug at once = TOXIC!