Disperse systems-dosage forms Flashcards
(24 cards)
What is a solution?
A homogenous mixture where a solute is dissolved into a solvent
What is molecular dispersion in solutions?
Its the even distribution of molecules throughout the solvent
what type of particles do solutions contain?
Small particles, such as ions or molecules.
Are solutions transparent or opaque?
transparent
do solutions seperate over time?
no
can solutions be filtered?
no
can solutions scatter light?
no
What is a disperse system?
A system where on phase (disperse phase) is distributed throughout a second phase (continuous phase or dispersant)
What is the disperse phase in a disperse systems?
The phase that is distributed throughout another phase
What is the continuous phase in a disperse system?
The phase in which the disperse phase is distributed, acting as a dispersant.
How are the phases in a disperse system related in terms of miscibility?
They are immiscible, meaning they do not mix completely and remain in contact as seperate phases
What is an example of a disperse system?
Oil droplets in water, where oil is the disperse phase and water is the continuous phase.
What is a colloid or colloidal dispersion?
A two-phase system of matter, a type of mixture intermediate between homogeneous and heterogeneous mixtures with particle sizes less than 1 µm.
How does a colloid compare to homogeneous and heterogeneous mixtures?
It is intermediate between homogeneous and heterogeneous mixtures.
What is a phase colloid?
A colloid where small droplets or particles of one substance (the disperse phase) are dispersed in another substance (the continuous phase).
What is a molecular colloid?
A colloid in which macromolecules are dispersed in a continuous phase.
What is the typical particle size in colloids?
Less than 1 µm.
What are the properties of colloids?
Tyndall effect
brownian motion
absortion
dialysis
electrophoresis
thixotropy
What is the tyndall effect in relation to colloids?
Colloids scatter light, light beams path through colloid is visible due to light scatter
What is the brownian motion?
Molecules of the liquid in motion, due to this larger particles of colloid are bombarded by smaller particles of the liquid. Motion of bombardment keeps colloid particles suspended.
What is adorption?
A chemical is associated to the surface of a second agent, it is often reversible. It can lead to conformational change.
