Exam 2 Flashcards
when doing calculations for liquid dosage forms, do you have to calculate the amount to qs with?
no just qs the final volume
when is equivalence used
applicable to hydro-ionizable compounds upon dissolution ( molecules that dissassociate in solution) ex. NaCl
does equivalence apply to non ionizable compounds?
no
examples: sucrose, dextrose
what is valence
the number of bonds formed by an atom in a covalent compound
how much is a mole?
hint: Avogadros number
6.022 x 10^23
how to deriv equivalence
take the molecular weight of the compound
(g/mol) and divide it by the valence (Eq/mol).
(g/mol)/(eq/mol)= g/Eq or mg/ mEq
what is mg %
how to convert from ratio strength to mg%
mg % per 100 mL of solution ex of how to convert from ratio strength to mg% 1:20,000= 1000 mg/ 20,000 mL 1000 mg/20,000 mL=xmg/ 100 mL x=(100x1000)/20,000 x=5 mg%
ratio strength
ex of how to convert from mg% to ratio strength
1 g :mL
5mg%
5 mg/100mL= 1000/ x mL
x= (100x1000)/5=20,000 mL
ratio strenth= 1:20,000
how to measure amounts that are below minimum weighable quantity ( MWQ) (aka serial dilution)
create a solution and perform dilutions in order to get the amount of drug needed.
for example. (kind of ) need to make multiple dilutions. for ex.
1. make a concentrated solution.
take a small portion of that and calculate how much solute is in it.
3.qs that to a new volume in order to create a more diluted solution. repeat until u can determine how much solution you need for desired mass of solute.
which products must always be refined
salicylic acid, suffer ppt, calamine, and zinc oxide
what is a suspension
liquid preparation that consist of solid particles dispersed through a liquid phase in which the particles are NOT soluble
what dosage form are suspensions NOT useful as
IV because they can cause an embolism
what’s dosage forms are suspensions useful as
oral
topical
opthalmic
IM
TYPES of liquid dosage forms
solutions, suspensions, emulsions
what are the purpose of suspensions
to provide a liquid form for H2O insoluble drugs
and provides an alternative to EtOH based solutions
why are oral suspensions usually formed in an aqueous base
because physiology is water based and water is inexpensive and ubiquitous
what kind of liquid dosage forms are oil soluble drugs made into sometimes
emulsions
can suspensions have soluble components
yes. however if all of the components dissolve, it is not a suspension, it is a solution
advantages of tablets/ capsules as drug source for suspensions
rapid decomposition
particle size already appropriate
disadvantages of tablets/ capsules as a drug source for suspensions
drug can be soluble in solvent, and could have been made into a solution if it were not for the excipients
tabs/capsules used in suspensions are generally more expensive
which part of a suspension is subject to (increased degredation)
only the portion in the solution
are drugs more stable in a suspension form or solution form? why?
drugs are more stable in suspension form because in solution form, drugs in solutions are subject to increased degredation
advantages of suspensions over sol.
- drugs are more stable
- much higher drug concentrations can be achieved
- alcohol can be avoided in many cases
disadvantages of suspensions over sol.
suspending agents are usually required
compounding procedures is more complicated
cant qs in graduate cylinder (due to settling of particles on the bottom)
must be shaken prior to administration
where do you qs a suspension
pre calibrated dispensing container
how do you qs a suspension
fill a graduated cylinder to a level corresponding to the final product volume
transfer graduates contents to the dispensing container
with dispensing container on smooth level surface, use grease pencil to mark the fluid level
empty /drain the dispensing container
what is levigation
wetting of insoluble powder agent in a minimal amount of qs media or levigating agent forming a smooth homogenous paste
what tools do you use to levigate
mortar and pestle
ointment slab and spatula
what is the purpose of suspending agents?
increase the products viscosity
and decrease particle settling rate
are suspending agents soluble in the qs media
may or may not be soluble in the qs media
difference between ratio strength and parts notation
ex: notation 3:4
ratio strength means 3 g of ingredient per 4 total grams of product. total 4 g of product
parts notations means 3 parts ingredient PLUS 4 parts of ingredient
ratio strength notation
X:Y
Tools used to achieve appropriate particle size for proper absorption for suspensions
sieves
micron gauge
feel
what determines sedimentation rate of particles
varies directly with particle size and particle density, but varies indirectly with suspension viscosity
sedimentation time
varies indirectly with particle size and density, varies directly with suspension viscosity
what is caking
tight aggregates particles interact with echother and makes it difficult or not possible to resuspend
what is important thing to remember before using suspension
SHAKE WELL
flucculation
formation of a loose aggregation of discrete particles held together
how to remember amy (they are flocked together??)
deflocculated suspension pro and con
pro: long sedimentation time
con: dense; difficult cake formed
flocculated suspension pro and con
pro: redisperses easily
con: short sedimentation time
physician order terminology for community pharmacy and institutional pharmacy
community: fill prescriptions
institutional pharmacy: execute medication orders
10% rule for parenteral products
if a volume to be added to an IV basis greater than 10% of the bas rated capacity, a volume equivalent to the add must be removed from the bag prior to the addition. if it is less than 10%, withdrawal prior to addition is not necessary
what technique should be used for parenteral compounding
aseptic technique
before beginning parenteral compounding, make sure to wat
take off jewelry, wash hands, and clean hood
after adding components to IV bag, make sure to what…
gently shake IV bag to check fo rparticulates and leakes
what is a tamper seal
added to IV bags additive port
when determining CrcL for peds, do we se the cockgraft- gault eq?
NO. that eq is for adults
how to do a serial dilutoin
- see that required KMNO4 id below minimal weighable quantity
- (confines must weight btw 200 +300 mg, must measure btw 5 and 100 mL)
- pick a # btw 100 and 300. lets say an ex. 225
- Part 1.
a.initial dissolution. weigh tout 225 mg of kmno4
place in beaker
b. dissolve in min amount of water
c. quantitatively transfer to a 50 mL GC w. purified water.
d. qs to 50 mL.
conc: 225 mg/50 mL - part 2: first dilution
a. measure 5 mL of initial dissolution, place in a clean 100 mL graduate. 225 mg/50mL=x/5 mL? ;X=22.5 mg - qs to 100 ml with purified water. mix by pouring
conc: 22.5/100mL - 2nd dilution.
22.5mg/100 mL=4.5 mg/X, X=20mL
a. measure 20 mL of the first dilution, place in clean 100 ml GC
b. qs graduate to 90 mL with purified water. mix by pouring
conc: 4.5 mg/90 mL= x/100 mL. x=5 g
5 mg /90 mL= x/100 mL; x=5%= 1:20,000
particle size for fine suspensions and emulsions
0.5-10 microns
particle size for ordinary suspensions and emulsions
10-50 microns
in suspension prescriptions, if an ingredient says it is to be qs, and it is not the qs media, what do u use it for
use a minimal amount levigate with it.
in solution prescriptions, if an ingredient says it is to be qs, and it is not the qs media, what do u use it for
dissolve the above ingredient in just enough solvent. figure out how much solvent by using the solubility. then add +10% so it could be dissolved.
