Emulsions, Mixture, Gels, Lotion.docx

EMULSION, MIXTURES, GELS/JELLIES and LOTION EMULSIONS - 2 phase system - Liquid is dispersed in another liquid in the form of droplets Components: 1. Dispersed Liquid - Internal phase - Discontinuous phase 2. Dispersion Medium - External phase - Continuous phase 3. Emulsifying Agent - Intermediate phase - Prevents the two immiscible liquids from coalescing Types of Emulsifying Agents 1. Natural a. Animal - Gelatin, egg yolk, casein, woolfat, cholesterol b. Vegetable - Acacia, tragacanth, carrageenan, pectin, caraya 2. a. b. c. d. -

Synthetic Finely Divided Solid Mg(OH)2, Al(OH)3, Mg trisilicate Colloid Kaolin, Bentonite Magma Anionic SLS Cationic Benzalkonium Cl, Cetyl pyridinium Cl e. Nonionic - PEG 400, spams, tweens f. Amphoteric - Lecithin

ACTIVITY

Antifoaming Emulsifiers (w/o) Wetting Agent Emulsifiers (o/w) Detergents Solubilizing Agents

HLB (HydrophilicLipophilic Balance) 1-3 3-6 7-9 8-18 13-16 15-20

Types of Emulsions 1. Simple Emulsion a. Water-in-Oil (W/O) - Water is dispersed as droplets in an oil or oleaginous material - Emollient, lubricating, or protective properties b. Oil-in-Water (O/W) - Oil dispersed as droplets in aqueous solutions - Most common type - Preferred for oral preparations 2. Multiple emulsion - O/W/O - W/O/W 3. Microemulsion - 100-1000A - (1A = 01. nn) Method of Preparation 1. Wet/English 2. Dry/Continental 3. Bottle/Forbes 4. Axillary Method – particles smaller Hand homogenizer 5. In situ soap - +lime H2O 6. Microemulsion – very stable Problems 1. Creaming - Temporary aggregation of internal phase - Reversible

EMULSION, MIXTURES, GELS/JELLIES and LOTION

2. Cracking - Permanent separation of internal phase - Irreversible 3. Phase inversion - w/o to o/w - irreversible Methods of Identifying Emulsion 1. Drop Dilution Test 2. Dye Solubility a. Sudan Red – oil soluble b. Amaranth Green – water soluble 3. Electric Conductivity Test - o/w 4. Fluorescence Test - w/o

MIXTURES - particle size >0.5 micrometers - aqueous liquid preparations containing suspended insoluble solid substances (suspensoid) Characteristics 1. very finely state 2. colloidal 3. palatability “Shake Well label” GELS/JELLIES - semisolid preparation - suspension made up of small inorganic particles - large inorganic particles interpenetrated by liquid 2 Classifications - inorganic and organic - hydrogels and organogels Hydrogels a. Organic hydrogels – pectin paste, tragancanth, jelly b. Natural and Synthetic gums – methylcellulose, Na CMC c. Inorganic hydrogels – bentonite gel, veegum, silica Organogels a. Hydrocarbon type – petrolatum, mineral oil/polyethylene glycol b. Animal and vegetable fats – lard, cocoa butter c. Hydrophilic organogels – carbowax bases, PEG ointment

EMULSION, MIXTURES, GELS/JELLIES and LOTION

LOTIONS - Washes - Lotio, lavare - Aqueous liquid or sometimes alcoholic preparation - Contains insoluble materials in the form of a suspension or emulsion - External application without rubbing - Itching, infection, allergy, pain - Oil-in water emulsions (cetearyl alcohol) - Water-in-oil - Without rubbing - Antibiotics, antiseptics, antifungals, corticosteroids, anti-acne, soothing, smoothing, moisturizing, protective Methods of Preparation 1. Trituration – Calamine Lotion 2. Chemical Reaction – white lotion (ZnSO4 and K2SO3)