Emultions Flashcards
Emultions
Small immiscible globules dispersed phase
Throughout avichle in witch it is not miscible
Types of despersions
Oil in water:dispersion where oil in internal and water is external
Water in oil:a phase where water in internal and oil is external
Emulsyfing agents
Hydrophilic with lipophilic parts provide a interface protective barrier and stabilize emulsion be reducing surface tenstion
Types of emulsifiers and stabilizers used in pharmaceutical industry
Carohydrate + protein substances+ high molecular weight alcohols give
(thikning and stabilizing agent)
O/W emulsions
4- wetting agents such as SLS and SPANS
5-finely divided solids as colloidal clays
Bentonite r +mg/al hydroxide
Substance which one substance microscopically dispersed insoluble particles suspended through another substance
Colloid
Orally less oil means
Reduced oil means better digestion and absorption
;why w/o is better to soften the skin
Because it resests drying and removal by water
While O/W is easily removed
On inbroken skin
It is better to use w/o because of the sebum thin film on skin wich is better wetted by oil
Is it possible to compound twp incompatable ingreadiants in an emulsion?/////
Yes yes yes
HLB system
Hydrophil/lipophil balance
Usual HLB and how much can it reach
1-20 and can reach 40
Hydrophilic HLB
Hydrophobic HLB
3-6 lipophilic w/o emulsion
8-18 hydrophilic o/w
7-9 wetting agents
Emultions vary in viscousty and can be prepared as
Liquids and semisolids
Many emultions is calssifed as other forms why examples
Because they fit a]other forms more specifically
Lotions/ointments/creams/lintments/vitamin drops
When do we consider an emultion unstable
If it forms aggregates and globules upon standing
2- if large globules or aggregates rise or fall to top/bottom
3-if all the part of liquid seperates to the top or bottom
Creaming of emultion
Upward or downword
A reversable process
The cream might be distributed
Should not be dispensed ethitics wise or appealing wise and it increases the risk of colscence
Coalesce
Irreversable breaking or cracking in the emultion and destructive to emultion unlike creaming
Might be caused from extreme hot or cold tempretures
The rate of seperation factors 3
Size the lower the better
Density difference the lower the better and
The increase outside viscousty is better
Thijckners as
Traganth and microcrystalline cellulose
Why do we use methylparabine and prophylparaben to preserve emultions
For o/w emultions because it is more common to fungi to grow than bacteria
Alcohol added to 12%-15% and paraben are
O/W preservation usually
How to dilute
W/O
O/W
W/O by adding oil
O/w by adding water
Always add the external phase
How do we prepare emulsions on high scale
By high speed impeller and rendered finer by colloid mill and large homogenizer forces liquid in a great pressure through small valve opening
To produce
100k L/hr
