exam 2 lecture 5 Flashcards
components of parenteral vehicles
isontonicity, osmolarity, osmolality
isotonicity
maintaining and possessing a uniform tension or tone
parenteral vehicles have ability to burst open blood and venous endothelial cells
concentrations over time
two different concentrations seperated by semi-permeable membrane –> given some time will equal concentration on each side.
diffusion
permeable membrane
high concentration to low concentration
solute moves from high concentration to lower concentration
osmosis
semipermeable membrane
water moves from higher concentration to lower concentration
impemeable membrane
nothing goes through
cell starves
permeable membrane
everything goes through
cell ends as an empty shell, dead again
semipermeable membrane
somethings can cross and others can’t
viable cell
cell membranes are semipermeable membranes
RBCs
shape allows membrane folding
different concentrations inside + outside
tendency to equalize concentrations
inject plain water –> hemolysis
how to measure risk
by knowing the osmolarity or osmolality of preparation
osmometer measures this property
colligative properties
properties that depend on quantity of molecular particles
osmolarity + osmolality are determined by total concentration of solutes dissolved
freezing point depression
lowering vapor pressure
osmotic pressure
elevation of boiling point
osmolarity
(#osmoles of solute) / (liter of solution)
osmolality
(# osmoles of solute) / weight (kg) of only solvent
osmolarity vs osmolality
when concentration is low –> closer and almost equal
when concetration is high –> very different
serum osmolarity
280 - 300 mOsmol/L