Emulsion

Emulsion

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  EMULSIONS Emulsion is aliquid medicament containing two immiscible liquids one which is broken down into minute globule, each globule being surrounded by a film of emulsifying agent and then dispersed throughout the other liquid. Naturally occurring emulsions: milk, egg yolk, butter Phases of emulsion 1) Internal, dispersed or discontinuous phase is that which is broken down into globules. 2) External, dispersion or continuous phase is that which surrounds the globules. 3) Intermediate phase or interphase is that which covers the globules & prevents coalescence. It is also known as emulsifying agent or emulgent. Types: Oil in water (o/w) & Water in oil (w/o) Differences Oil in water (o/w) Water in oil (w/o) 1 Free dilution by external phase i.e. with water Free dilution with oil 2 The continuous phase is stained by methylene blue The continuous phase is stained by sudan III 3 It has milky white appearance It has a waxy and translucent appearance 4 It is a good conductor of electricity It is a bad conductor of electricity 5 Water soluble emulsifying agents are used e.g. acacia, casein saponins egg yolk and soaps formed from monovalent base. Fat soluble emulsifying agents are used e.g. wool fat resins & soaps formed from divalent base(ca++, Mg++, Zn++) 6 It has uniform fluorescence e.g. Cod liver oil emulsion & castor oil emulsion It has spotty fluorescence e.g. Cold cream Emulsifying agents: They form an intermediate phase between the dispersed & the continuous phase. They usually reduce the interfacial tension between oil & water and thus aid in dispersion of one liquid in the other. They are added to ensure uniform dispersion & to provide stability to preparation. 1) Gums: Acacia , tragacanth 2) Proteins: casein, egg yolk 3) Carbohydrates: starch mucilage, malt extract 4) Soaps: soft soaps, hard soaps
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  Stability of emulsion Astable emulsion is one in which the globules retain their initial character & remain uniformly distributed throughout the continuous phase. Any deviations from the above, result in unstable emulsion. Physical instability in an emulsion may lead to: (i) Cracking or breaking or separation of emulsion: It means destruction of the emulsion system, coalescence of the dispersed globules & separation of the two phases into two layers. (ii) Creaming or sedimentation of an emulsion: It occurs when oil / fat arise on the surface but still remains in the form of globules. Hence the instruction “shake well before use” should be written on the label. It is minimized by decreasing the size of globules & increasing the size of the external phase. Causes of failure to make a good emulsion: 1) By using wrong mortar & pestle. 2) By not using a dry measuring cylinder. 3) Using incorrect proportion of ingredients. 4) Diluting the primary emulsion before it is perfectly formed. 5) By improper trituration.
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  Cod liver oilemulsion Object: To prepare & dispense 30 ml of Cod liver oil emulsion Prescription: Dr. Kanav Sharma, MBBS, MD Reg. No: 12345 Address: A 45, Malviya Nagar, Jaipur Mob. No: 9887123456 Email: [email protected] Amit 10 years Male Diagnosis- Rickets RX Cod liver oil 6ml Gum acacia 1.5gm Aqua ad 30ml M.ft: Mix and prepare an emulsion. Send such 30 ml. Signa: 1) Shake well before use. 2) One tablespoonful to be taken twice a day after meals. 09/04/2019 Kanav Method of preparation of emulsions :- 1) Wet gum method 2) Dry gum method Wet gum method: Weigh 1.5 gm of gum acacia, add 3 ml of water in mortar & triturate it until a mucilage is formed, then add cod liver oil drop by drop while triturating till primary emulsion is formed. Add water upto 10ml to primary emulsion with constant trituration, transfer it to the measuring
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  cylinder & adjustit to the required volume by adding water. Dispense it to the dispensing bottle. Cork it & label it. Label 30 ml Cod liver oil emulsion Shake well before use Amit 10 years Male Direction: one dose to be taken twice a day after meals. 09/04/2019 Kanav Pharmacy Lab. Dept. of Pharmacology SMS Medical College &Hospital, Jaipur Uses of Cod liver oil emulsion: 1) As a prophylactic for infants & children to prevent rickets. 2) As a dietary supplement in infants & children for promoting growth & nutrition. 3) As a curative in rickets, osteomalacia & in defective calcification. 4) Given to undernourished children with tuberculosis & other wasting diseases like caries of bones, chronic joint diseases for promoting growth. 5) As a tonic to a convalescent person. Action of individual ingredients: 1) Cod liver oil: pale yellow liquid, contains glycerides & unsaturated fatty acids. It is obtained from liver of cod fish (Gaddus callarias). One gram of cod liver oil contains 85 units of vitamin D & 600 units of Vitamin A. 2) Gum acacia: It is a dried gum exudate obtained from branches of Acacia Arabica tree. It acts as an emulsifying & suspending agent. Advantages (of its being used as an emulsifying agent): It is used in preparing most of O/W type of emulsions. No preservative is required. As it is tasteless & has good covering property it makes the emulsion palatable.
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  Disadvantages: It cannotbe used for preservation of W/O emulsion or emulsion used for external use because here water is in internal phase & drying will cause stretching of skin. Viva questions: 1) Define emulsion & its types? 2) What are emulsifying agents? Which is the most commonly used emulsifying agent & why? 3) What is creaming & breaking of emulsion? 4) What is the daily requirement, various sources & indications of Vitamin D? 5) What is Hypervitaminosis D? 6) What is the daily requirement, various sources & indications of Vitamin A? 7) What is Hypervitaminosis A?