Lab 7 Flashcards
common adverse effects observed in electrolyte formulations are related to what?
the high osmolarity (or osmolality) and/or local irritant effects
many drugs and excipients are ____ in the presence of electrolytes and minerals, resulting in _____
INCOMPATIBLE, resulting in PRECIPITATION
electrolyte solutions containing sodium, potassium salts of chloride and/or citrate are used to do what?
replenish electrolyte loss that results from dehydration and use of certain diuretics
electrolyte solutions can be prepared as ___ or as ____
powders for reconstitution or as concentrated solutions
highly hypertonic ORAL preparations must be …………. before administration to avoid _______
must be dissolved or diluted with the appropriate quantity of water before administration to avoid GI EFFECTS
hypertonic PARENTERAL solutions must be…………to avoid ………
must be diluted appropriately with IV fluids OR should be administered via large veins (ie: superior vena cava) to avoid LOCAL TISSUE IRRITATION AND OTHER ADVERSE EVENTS
____ can occur when highly concentrated electrolyte solutions are mixed with some drugs
incompatibilities such as PRECIPITATION and DEGREDATION
osmotic pressure is defined as….
pressure exerted by the molecules and ions present in solution on the SEMIPERMEABLE MEMBRANE
osmotic pressure is dependent on…
the number of dissolved particles (molecules and ions) in solution
what can you say about the osmotic pressure of NON electrolytes vs electrolytes
non-electrolytes do not dissociate.
therefore, the number of particles that affect osmotic pressure is DIRECTLY and only related to the number of moles
in the case of electrolytes, they dissociate into ions. therefore, osmotic pressure depends on IONIC CONCENTRATION
electrolytes dissociate into ions. therefore, osmotic pressure depends on ionic concentration
how is the ionic concentration calculated ??
using the percentage dissociation and molar concentration of the solutions
do insoluble ingredients (suspended in the solution) exert osmotic pressure?
NO
osmotic pressure is recorded in terms of ___ or ___
osmolarity or osmolality
define osmolarity
the concentration of osmotically active particles (molecules, ions) per unit VOLUME of SOLUTION (L)
define osmolality
the concentration of osmotically active particles (molecules, ions) per unit MASS (kg) of SOLVENT
true or false
mass does not change with temperature
true
true or false
volume does not change with temperature
FALSE — volume does change with temperature
which is more reliable —
osmolarity or osmolality
OSMOLALITY VALUES ARE MORE RELIABLE
this is so because volume changes with temperature while mass does not
when are osmolarity and osmolality values used interchangeably?
when the density of the pharmaceutical solution is approximately 1
substances that are NOT completely dissociated have a _____ osmotic pressure than those that are 100% dissociated.
WHY
substances that are NOT completely dissociated have a LOWER osmotic pressure than those that are 100% dissociated
this is so because the number of ions (particles) in the product is higher in those substances that are 100% dissociated
tonicity is the measure of…..
the osmotic pressure gradient between 2 solutions separated by a semipermeable membrane
TONICITY IS ONLY INFLUENCED BY…
solutes that cannot cross the semipermeable (plasma) membrane
water readily diffuses through the plasma membrane.
why?
to maintain osmotic equilibrium on either side of the membrane
in a cell, water moves in and out of the cell between the ___ and the ____ to maintain the osmotic pressure
ECF (extracellular fluid) and ICF (intracellular fluid)
the normal osmolality of ICF and blood plasma ranges between____ -_____ mOsm/kg
285-290
a solution is isotonic when…
its osmolality is similar to that of blood plasma
when the solution is isotonic, explain the movement of water
the movement of water across the cell membrane is at equilibrium and the cell volume and size does not change significantly
a solution is hypertonic when….
its osmolality is higher than that of blood plasma
water from the cell moves into the solution and the cell decreases in volume and size.
the cell will crenate
a solution is hypotonic when…
its osmolality is lower than that of blood plasma
water from the solution moves into the cell and the cell increases in volume and size. the cell will eventually burst (hemolysis)
what can contribute to osmotic pressure and tonicity of a pharmaceutical preparation?
both the API and the excipients
hypertonic oral solutions can present issues such as ___ and _____
give examples of specific components that cause these issues
gastric intolerance (sorbitol and iron)
and osmotic diarrhea (sorbitol and glycerin)
hypertonic injectable solutions can cause..
local irritation, thrombophlebitis, and hemolysis
what is the osmolar range for the GI tract?
127-357 mOsm/kg
what buffers the medication to a safe pH and osmolar range before it reaches the duodenum?
(therefore, for oral solutions less than 700mOsm, there is no serious problem)
saliva, mucus, and gastric juices
what organ is exceptionally sensitive to hypertonic solutions and osmolar loads?
the small intestine
osmotic diarrhea results due to what?
the movement of water into the gut
oral solutions greater than ____mOsm/kg should not be administered undiluted
2000mOsm/kg
what are minerals? give 2 examples
minerals are macronutrients essential for body function
ex: iron, calcium
many mineral supplements are available OTC.
the content of these elements in the preparation must be expressed in terms of the elemental content.
WHY?
to avoid dosing errors
an EQUIVALENT of an element is…
the number of moles of the element that combine with 1 mole of hydrogen
the number of equivalents in an element or compound is calculated using ___ or ____
valency or chemical reaction
true or false
the number of equivalents present in the element is generally equal to its valency
true
the number of equivalents present in the COMPUND is generally equal to…..
the highest valency in the molecule
