What type of drug can be delivered directly via intracerebral injection, via systems that utilize brain vessel pH or via food or supplements?
Endogenous neurotransmitters
What is a Pulse delivery system?
A delivery system made or erodible polymers
Each layer of polymer has a different drug loads
The drug is released during a skin pore opening electric pulse
What are Hydrogels?
Three dimensional crosslinked networks of homopolymers, copolymers or macromers
What is the term for a three dimensional, cross-linked network formed from hydrophilic monomers, homopolymers or macromers?
A hydrogel
Hydrogels can be designed to accept different simuli (T/F)?
True
They can accept stimuli from:
pH, ionic strength, Chemical species, Enzyme-substrates, magnetic, thermal, electrical and Ultrasound irradiation
What type of drug delivery system can be designed to accept stimuli from pH, ions, Chemical agents, Enzyme-substrate interactions, Magnetic fields, Heat, Electricity and ultrasound irradiation?
Hydrogels
What is diffusion?
A process of mass transfer via random Brownian motion
What is the process of mass transfer via random Brownian motion called?
Diffusion
Perfume, Osmosis and Dialysis are all systems that are based on what basic principal?
Diffusion
What four reasons were given in class for the importance of diffusion to pharmacy?
Dissolution of drugs
Dialysis
Lyophylization
Ultra-filtration
What is the equation for Fick’s law of diffusion or Flux?
J = dM/(S x dt)
M = grams of material passing over the barrier in time t
S = cross-section area of barrier
J = flux
What is Fick’s first law of diffusion?
J = -D (dC/dx)
D = diffusion coefficient of the solute (in cm2/sec)
The Diffusion coefficient of Fick’s first law is a function of what five properties?
Temp
Pressure
Conc.
Solvent properties
Chemical nature of solute
What is Fick’s second law?
D = diffusion coefficient of the solute in cm2/sec
t = time
x = position in barrier
What five important applications for Fick’s laws were discussed?
1.) Development of controlled-release dosage forms
2.) Bioavailability of dosage form
3.) lyophilization
4.) Efficiency of dialysis membranes
5.) Physiological phenomena (lung gas exchange, renal filtering)
What equation would you use to predict the bioavailability of a drug via its diffusion coefficient?
Fick’s law
What equation would you primarily use to calculate the diffusion coefficient?
