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Emulsion Chemistry for Cosmetic Chemists Society of Cosmetic Chemists September 24, 2006. Shattering Myths about R&D. This is what regular people imagine R&D people to be like but this is not true!. Actual Cosmetic Chemist at work. Emulsion Chemistry Meet Your Instructor.
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Emulsion Chemistry for Cosmetic Chemists Society of Cosmetic Chemists September 24, 2006
Shattering Myths about R&D This is what regular people imagine R&D people to be like but this is not true!
Actual Cosmetic Chemist at work.
Emulsion Chemistry Meet Your Instructor • Perry Romanowski • Alberto Culver • Senior Project Manager Hair Care Innovation • DePaul University • BS. In Chemistry, Biology • MS. In Biochemistry • SCC Area II Director
Emulsion ChemistryMeet your instructor Beginning Cosmetic Chemistry by Schueller and Romanowski
Emulsion ChemistryMeet your instructor 3rd fastest juggling marathoner in the world justyouraveragejoggler.com
Emulsion ChemistryAudience Survey • Undergrads? • Grad students? • Job seekers? • Entrepreneurs?
Emulsion Chemistry Outline – What you should learn • Learn about emulsions • What they are • Where they are used • How you make them • Practical information
Emulsion Chemistry: Presentation Agenda • Science of emulsions • How to make them
Emulsion Chemistry: Cosmetics • Cosmetics are all about changing / improving surfaces
Emulsion Chemistry: The Problem - Oils • Oils are excellent cosmetic materials • Improve surface feel • Protect • Aid in moisturization • Reduce static • Shine • Don’t wash away • Oils have drawbacks • Tacky, greasy • Cost too much
Emulsion Chemistry: The Problem • Oil & Water Do Not Stay Mixed • Why? • Lower free energy when separate • Why? • Hydrogen Bonding • Oils are non-polar • Size of molecules
Emulsion Chemistry: The Solution • Add energy to the system • Agitation • Heat • Need something to stabilize • Surfactants or Emulsifiers
Emulsion ChemistryEmulsifier – The Stabilizer • Lipophilic tails & Hydrophilic heads • Reduce interfacial surface tension • Helps disperse oil in water • Forms micelles in solution
Emulsion Chemistry:Micelle formation • Oil breaks into tiny droplets (particles) • Hydrophilic heads align with water • Lipophilic tailsalign with oil • Note: More structures than this formed in solution. Depends on surfactant concentration
Emulsion Chemistry: The Solution Molecules in Motion
Common Emulsions Peanut Butter Salad Dressing Milk
Emulsion ChemistryEmulsions • Pseudo-Stable mixtures of oils & water • Three phases • Internal Phase • External Phase • Emulsifier
Emulsion ChemistryEmulsions • Why are they useful? • Improved feel • Easier to apply – Shear thinning • Less chemical exposure = safer • Use the right amount • It’s generally cheaper!
Emulsion ChemistryEmulsions - Particles • The importance of particle size • Clarity • Stability • Characterization • Macroemulsions • Microemulsions (also Nanoemulsions)
Emulsion ChemistryEmulsions - Types • Type of emulsions • Oil in Water • Water in Oil • Multiple emulsions
Emulsion ChemistryOil in Water – O/W • Internal phase = oil • External phase = water • Advantages • Easiest to formulate • Least expensive • Best feel – cooling effect • Disadvantages • Less oil delivered • Not as effective for dry skin • Not water-resistant
Example Product – O/W St. Ives Vitamin E Lotion Water (Aqua), Glycerin, Mineral Oil (Paraffinum Liquidum), Stearic Acid, Glycol Stearate, Stearamide AMP, Petrolatum, Dimethicone, Tocopherol, Tocopheryl Acetate, Chamomilla Recutita Flower Extract (Matricaria), Helianthus Annuus Extract (Sunflower), Sambucus Nigra Flower Extract, Primula Veris Extract, Theobroma Cacao Seed Butter (Cocoa), Glyceryl Stearate, Cetyl Alcohol, Triethanolamine, Acetylated Lanolin Alcohol, Cetyl Acetate, Magnesium Aluminum Silicate, Carbomer, Propylene Glycol, Propylparaben, Methylparaben, DMDM Hydantoin, Disodium EDTA, Sorbitol, Fragrance (Parfum), Yellow 5 (CI 19140) Other Products Hair conditioners Sunscreen Wrinkle Creams
Emulsion ChemistryWater in Oil – W/O • Internal phase = water • External phase = oil • Advantages • Waterproofing possible • Most effective for dry skin • Better stability • Disadvantages • Oily, tacky feel • More expensive
Example Product – W/O Philosophy hope in a tube, Firming cream Water (aqua), Squalane, Mineral Oil, Glycerin, Isocetyl Stearoyl Stearate, Petrolatum, Butylene Glycol, Polyglyceryl 2 Diisostearate, PEG 30 Dipolyhydroxystearate, Ceresin, Polyethylene, Microcrystalline Wax, Magnesium Sulfate, Phytosteryl/Octyldodecyl/Lauroyl Glutamate, Dipalmitoyl Hydroxyproline, Tocopheryl Acetate, Polysorbate 80, Bisabolol, Potassium Ascorbyl Tocopheryl Phosphate, Iron Oxide (CI 77492, CI 77491 and CI77499), Methylparaben, Diazolidinyl Urea, Ethylparaben, Tetrasodium EDTA
Emulsion ChemistryEmulsions – Differences • Is it O/W or W/O? • Dilution – O/W disperses more easily • pH – O/W has consistent pH • Conductivity – O/W conducts electricity
Emulsion ChemistryMultiple Emulsions • Multiple phases • Oil in Water in Oil (O/W/O) • Water in Oil in Water (W/O/W) • Advantages • More effective than Oil in Water • Less greasy than Water in oil • Time release, active delivery possible • Disadvantages • Hard to manufacture • Not always stable
Just for funCosmetic Chemistry Challenge #1 • Cosmetic Research Quiz – Which story is fake? • 1. Hair can expose eating disorders. • 2. Drinking spearmint tea can speed hair growth. • 3. Ocean oil spills can be cleaned up with hair. • 4. Geckos use hair to stick to surfaces.
Emulsion Chemistry Emulsion - Stability • Emulsions are inherently unstable • Second Law of Thermodynamics • Good emulsions last a long time • But eventually, these things happen…
Emulsion Chemistry:Emulsions - Stability Problems • Flocculation • Coalescence • Creaming • Inversion
Emulsion ChemistryEmulsion – Stability • Formulators fight the Second Law! • Prolong the life of the product • How? • Emulsifiers • Thickeners • Particle Size • Testing for stability • Viscosity Checks • Appearance
Emulsion Chemistry:Elements of the Formula • Formula Components • Oil Phase • Hydrophobic materials • Oils, esters, fragrances • Aqueous phase • Extracts, colorants • Humectants • Thickeners • Emulsifiers • Holds it all together
Emulsion Chemistry:Emulsions – Oil Phase • Examples in cosmetics • Lanolin and derivatives • Natural Oils / Fats • Waxes • Silicones • Esters • Emollients
Emulsion Chemistry:Emulsions – Aqueous Phase • Anything that is soluble in water • Examples in cosmetics • Water • Hydrolyzed proteins • Humectants • Glycols • Extracts • Dyes • Polymers, thickeners • Acids, etc.
Emulsion Chemistry:Emulsions – Aqueous Phase • Thickeners to stabilize the emulsion • Examples in cosmetics • Carbomer • Locust bean gum • Xanthan gum • Cellulosics • PVP/Decene copolymer
Most common For Cosmetic Emulsions Emulsion Chemistry:Emulsions – Emulsifiers • Surfactants • Anionic • Carboxylic acids : Soaps • Sulfonic acids: Sulfosuccinate esters • Cationic • Amines : PEG Alkyl amine • Quaternaries: Tetraalkyl ammonium salts • Amphoterics • Phospholipids • Nonionics • Fatty Alcohols • Esters • Polymers
Glyceryl Stearate PEG-100 Stearate Stearyl Alcohol Cetyl Alcohol Laureth-23 Steareth Alcohol Cetyl/PEG/PPG 10 Dimethicone Stearic Acid Emulsion Chemistry:Typical Emulsifiers
Emulsion Chemistry:Emulsions – HLB • How to pick emulsifiers • Mostly, it’s trial and error • Modify starting formulas • Or Learn to use HLB
Less polar (low HLB) More Polar (High HLB) Emulsifiers – HLBHydrophobe/Lipophobe balance • Varying degrees of non-polar & polar character. • Specific oils need specific surfactant polar/non-polar character to be effectively emulsified.
Emulsion Formulation:HLB System • HLB system - • William Griffin from Uniqema in 1949 • System to quickly create stable emulsions • Works best with nonionic surfactants • Ingredients are assigned an HLB value • (based on molecular weight & solubility) • Lower values are less water soluble • Oils are assigned HLB values • Amount of emulsifier is calculated • Where to learn more • http://www.specialchem4cosmetics.com/services/editorials.aspx?id=1928
Emulsion Chemistry:Emulsions – HLB Common Oils used and the HLB needed to Create an emulsion
Emulsion Chemistry:Emulsions – HLB Chemical Ethylene Glycol Glyceryl Stearate Sorbitan Palmitate Laureth-4 Nonoxynol-9 Polysorbate-80
Emulsion Chemistry:Emulsions – HLB Formula • HLB is only a good approximation • Doesn’t always work • Multiple emulsifiers improve stability • More emulsifier is used than needed
Just for funCosmetic Chemistry Challenge #2 • Cosmetic Research Quiz – Which story is fake? • 1. Drinking tea can protect your skin. • 2. Smearing black raspberry on your skin will protect it. • 3. Oil used to make French fries may help repair damaged skin. • 4. Playing an instrument is good for your skin.