Selasa, 03 Juli 2012

Teori Emulsi / Emulsion ( part 1 )

Definition of emulsion : A heterogeneous system.Which is thermodynamically unstable, consisting of at least two immiscible liquid phases, where one of them dispersed, the other fluids in the form small droplets, the size 0.25 to 20 μm. Require additives to stabilize the emulsion system

Emulsion system consisting of :
Dispersed phase or the internal phase (consist of = 20-50%)
Dispersing phase or eksternal phase ( Consist of = 50-80% )
Emulsifier as a material that function is to stabilize the emulsion (consist 5-10% of the dispersing phase)

Application :
1. Oral Emulsion
    Convenience in oral use
    Example: The fish oil that tastes so bad it made ​​the emulsion can be covered the taste and increasing the
                   speed of absorption in our body

2. Parenteral Emulsion
    Can be used for intramuscular or intravenous use when oral usage is not possible or for controlled
    drug release
    Example : Emulsi vaccine emulsion

3. Topical Emulsion
    Dermatology application aims to obtain a local effect on a particular place.
    Example : Dermatology Emulsion usually made in  a cream and ointment

                                                          Three Type of Emulsion

1. Gas emulsion: an emulsion in the gas dispersing medium. Ex: hairspray, bayfresh, Baygon spray
2. Solid emulsion: an emulsion in a solid dispersing medium. Ex: jelly, cheese, butter
3. Liquid Emulsion: meruapakan emulsion in water dispersing medium. Eg: milk, coconut milk, vaccine

Types of liquid emulsion:
1. Oil in Water ( m/a = o/w )
2. Water in Oil ( a/m = w/o )
3. Oil in Water in Oil  ( m/a/m = o/w/o )
4. Water in Oil in Water ( a/m/a = w/o/w )

Determine the type of emulsion :

1. Dilution test: Dilution of the dispersed phase
2. Dye test: water-soluable to color a / m, observation through a microscope
3. Conductivity: emusli m / a can conduct electricity.
4. Fluorescens: emulsion of a / m because the oil can be berfuorescent in the UV.
5. CoCl2 + filter paper: the color will change of blue -> pink (for o / w)

Theory Of Emulsification:

Why be back again!?

If 1 cm3 transformed into a dispersed phase droplet-droplet size of 0.01 μm with 1cm3 in the dispersing phase. Then the outer surface of the droplet was = 600 m2. Wider of a basketball court

Due to the greater surface area, then the implications for the free energy surface increased by 8 calories

Free energy surface is the energy required for droplet-droplet had formed recombine


Stable Emulsion  ???????

Use Emulsifier
A substance that can stabilize an emulsion

Mechanism of Emulsifier
Consists of hydrofilic part (the water loving) and lypophilic part (the oil loving)

1. Reduce interfacial tension between the  water phase and the oil phase.
2. Reduce the interfacial free energy
3. Form a rigid film layer as a mechanical barrier to prevent  flocculation and coalescence globule

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