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40 Cards in this Set

  • Front
  • Back
oil
lipid or nonaq
w/0
internal phase - h20
o/w
external phase - h2o
type of emulsion formed is determined by - Ideal Emulsion
- relative phse volumes emulsifying agt

max conx of internal phase is 74% -> < or eq 74% oil
choice of emulsifying agt
more impt than the relative phase volumes in determining final emulsion type
emulsifying agt
any compd that lowers the interfacial tension and forms a film at the interface
effectiveness of emulsifying agt
depends on

chemical structure
conc
solubility
pH
physical prop
electrostatic eff
true emulsifying agt ( primary agts)
form and stabilize emulsions by themselves
stabilizers(auxilliary agts)
do not form acceptable emulsions when used alone but assist primary agts in stabilizing the prodt
ex: inc viscosity
emulsifying agts
natural
synthetic
natural emulsifying agts
acacia
tragacanth
agar
pectin
gelatin
methylcellulose
carboxymethylcellulose
synthetic emulsifying agts
anionic
cationic
nonionic
acacia
good
stable emulsion of low viscosity
cream easily
incompatible w/ peruvian balsam, salts and carbonates
acidic
stable at pH 2-10
negatively charged
dehydrates easily
requires preservative
tragacanth
stable smulsion
coarser than acacia
ionic and difficult to hydrate
used for eff on viscosity
less than or eq to 1/10 of amt used for acacia needed
agar
anionic gum
inc viscosity
stability affected by heating, dehydration and destruction of charge
susceptible to miscrobial degradation
pectin
quasi-emulsifier
used in the same proportion as tragacanth
gelatin
provides good emulsion stabilization in a conc of 0.5%-1%

depends on isoelectric pt could be anionic or cationic
type a gelatin(+)
prepared from acid treated precursor
used in acidic media
type B gelatin (+)
prepared fr alkai treated precursor : used in basic med
methylcellulose
nonionic
induces viscosity
used as 1 degree emulsion w/ mineral oil and cod liver oil
yields o/w emulsion
used in 2% conc
carboxymethylcellulose
anionic
used to inc viscosity
tolerates alc up to 40%
forms basic soln
precipitates in presence of free acids
surfactants
amphiphilic molecules
HLB balance
imbalance of surfactants
0-3
antifoaming agt
4-6
w/o emulsifying agt
7-9
wetting agt
8-18
o/w emulsifying agt
13-15
detergents
10-18
solubilizing agts
anionic synthetic agts
sulfuric acid esters (sod lauryl sulfate)

sulfuric acid deriv (dioctyl sod sulfosuccinate)

soaps
soaps
externaluse

inc pH
sensitive to the addition of acids and electrolytes
alkali soaps
hydrophilic
form o/w emulsion
metallic soaps
o/w emulsion
monovalents soaps
o/w emulsion
polyvalent soaps
w/o emulsion
cationic synthetic agts
benzalkonium cl
used as surface active ing in 1% conc

incompatible with soaps
nonionic syn agts
resistant to the addition of acid and electrolytes
sorbitan esters
spans
low HLB value (1-9)
hydrophilic
form w/o emulsion
tweens
polysorbates
hydrophilic
o/w emulsion
form complexes w/ phenolic compd
inc hlb calue (11-20)
prepare emulsion
wet gum (english) mtd
dry gum (continental) mtd
bottle mtd
nascent soap mtd