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11 Cards in this Set
- Front
- Back
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Emulsion preparation
Dry method (continental) |
-A primary emulsion is first prepared then diluted to the final emulsion
Primary emulsion -oil:water:gum) 4:2:1 Gum mixed with oil then water is added at once and mixed -hen dilute with water ( + water soluble additives) -il soluble additives dissolve in oil -lcohol should be diluted. Volatile oil ( 3:2:1 or 2:2:1). |
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Emulsion preparation
Wet method ( English) |
-imilar to the dry method but during primary emulsion preparation the water is mixed first with gum then oil is added portion wise.
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Emulsion preparation
Forbes Bottle |
-ethod for volatile oil or low viscosity oil.
- part of acacia and 2 parts of oil shaken in bottle -hen equal volume of water is added and shaken in portions. Then qs with water |
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Emulsion preparation
Insitu soap( Ca soap) |
-ix equal volumes of lime water with oil (olive oil + lime = Ca oleate)
-Ca salts forms w/o emulsion -More oil or oleic acid is added to prevent lime water droplet from collecting on the surface. |
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Microemulsions
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-Thermodynamically stable emulsions
-Transparent -10-100 nm -Prepared by agitating oil, water and surfactant (HLB 15-18) Tween 60, 80 -Advantages: Rapid oral absorption, enhanced transdermal absorption |
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Creaming of emulsion
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-Aggregates of the internal phase globules rise to the top or fall to the bottom of the emulsion
-Reversible, but not acceptable Follow stokes’ law V = (2/9)r2(d1-d2)g/µ Ideal emulsion would have 1:1 oil: water |
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Emulsion Breaking
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-Coalescence of the globules of the internal phase, and separation of a layer.
-Irreversible |
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Emulsion type determination
w/o |
-Addition of water soluble dye (methylene blue): Float on the surface
-Electric currency: Fails to carry current -Dilution with water: Will float |
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Emulsion type determination
o/w |
-Addition of water soluble dye (methylene blue): Disperse uniformly
-Electric currency: A current will pass though -Dilution with water: Will mix easily |
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Span
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(Sorbitan Esters)
-Span 80 or = Sorbitan monooleate -Span 20: -Span 60: Sorbitan monostearate |
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Tween
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Polysorbates
-Tween 80 = polyoxyethylene sorbitan monooleate -Tween 20 = polyoxyethylene sorbitan monolaurate -Tween 60: |
