Emollients and Fatty Acids Quiz

Cosmetics and Skin Care

• Cosmetics include non-leaching agents, antioxidants, peptides, and growth factors.
• Examples: glutathione, Pharmaceuticals, and Cosmeceuticals.

Cosmetic Science

• Cosmetic Science is a multidisciplinary field that encompasses concepts and principles from different fields of science.
• Definition of Cosmetics: substances or preparations intended to be placed in contact with external parts of the human body to clean, perfume, change appearance, correct body odours, protect, or keep them in good condition.

Cosmetics vs. Drugs

• Cosmetics are intended to affect the appearance of the body, while drugs are intended to treat or prevent diseases.
• Example: Paraben-free products, which are linked to breast cancer and other endocrine disturbances.

pH Balanced

• Claim to make consumers believe that the product will be less irritating.
• Normal pH of the skin is acidic.

Dermatologist-recommended Products

• Probably based on product surveys and endorsement by dermatologists.

Chemistry of Cosmetic Consumer Products

Importance of Ingredient Selection

• Surfactants: reduce the surface tension of water, form micelles, and have different types:
  • Cationic: conditioning for skin and hair, skin is negatively charged, and opposite attracts = coating.
  • Amphoteric: cleansing, bactericidal/bacteriostatic, softening, and foam building.
  • Nonionic: active due to alcohol or ethylene oxide head, emulsion stabilizing, conditioning, and solubilizing.

Uses of Surfactants in Cosmetics

• Cleaning/detergency
• Foam formation
• Thickening
• Emulsification

Emulsifiers

• Stabilize emulsions, classified based on ionic charge:
  • Positively charged
  • Negatively charged
  • Non-ionic

Types of Surfactants in Cosmetics

• Anionic: foam building and cleaning, may be irritating
• Amphoteric: cleansing, bactericidal/bacteriostatic, softening, and foam building
• Nonionic: emulsion stabilizing, conditioning, and solubilizing

Emollients and Moisturizers

• Emollients: soften or soothe the skin, correct dryness and scaling, and replenish lipids.
• Examples: oils, fatty acids, lanolin, cholesterol, and esters of fatty alcohols and fatty acids.
• Moisturizers: add or retain moisture, generally more water-soluble than emollients.
• Subclasses of Moisturizers:
  • Humectants: prevent drying of preparations, hygroscopic.
  • Emollients: replenish oils and lipids.
  • Occlusives: hydrophobic/water-repellent, keeps the moisture in.
  • Enhancers of the Skin Barrier: skin rejuvenators, enhance barrier function of the skin.

Waxes, Thickeners, and Active Ingredients

• Waxes: long chain FA, solid at room temperature, has sealing properties.
• Examples: beeswax, carnauba or candelilla waxes.
• Thickeners: cellulose, carbopol, bentonite clays, carrageenan, and pectin.
• Active Ingredients: act physiologically to lighten, tighten, and firm the skin.
• Examples: fruit acids, alpha-hydroxy acids, aluminum chlorohydrate, salicylic acid, benzoyl peroxide, and dimethicone.

Pigments and Dyes

• Incorporated to impart color.
• Types: face powders, fillers, pearls, organic pigments, and dyes.
• Examples: kaolin, talc, silica, mica, oils, zinc stereate, and D&C vs. FD&C.

Preservatives and Antioxidants

• Preservatives: prevent microbial contamination and rancidity.
• Examples: parabens, phenoxyethanol, and antioxidants.
• Antioxidants: prevent formations of free radicals in the skin.
• Examples: vitamin E, butylated hydroxytoluene (BHT), and functional silicones.

Other Additives

• Silicone blends: increase substantivity or durability.
• Dimethicone/vinyldimethicone crosspolymers: adds viscosity and provides a dry, powdery feel.
• Functional silicones: made to adjust hydrophilicity, rheologic properties, and compatibility to organic compounds.
• pH buffers: match the formulation's pH with that of the application surface.
• Examples: citric acid, lactic acid, sodium hydroxide, and triethanolamine.
• Plasticizers: added to films to soften and impart flexibility.
• Examples: camphor, castor oil, and glyceryl tribenzoate.
• Propellants: added to aerosol preparations to maintain pressure and help expel contents.
• Examples: isopentane, butane, sobutane, and propane.
• Solvents: dissolve components, provide a vehicle, or contribute to texture.
• Examples: polar, semi-polar, and non-polar solvents.

Physical Absorption

• UVA and UVB filters.
• Examples: PABA derivatives, cinnamates, salicylates, benzophenones, avobenzone, titanium dioxide, and zinc oxide.

Vitamins and Skin Care

• Vitamins: antioxidants, skin protectants, and skin rejuvenators.
• Examples: vitamin E, vitamin C, vitamin A, vitamin D, vitamin B6, and biotin.
• Vitamin E: non-enzymatic antioxidant, stabilizes biological membranes, and topical application for sun-damaged skin.
• Vitamin C: water-soluble non-enzymatic antioxidant, protects from UVB damage, and stimulates collagen formation.
• Vitamin A: stimulates cell proliferation and cell renewal, increases collagen content, and increases elasticity and barrier function of the skin.
• Biotin: good for nails and hair due to its effect on keratinization.
• Vitamin D: UV barrier.
• Vitamin B6: for decreasing sebum production.
• Beta-Carotene: partnered with vitamin E and C to protect the skin against UV damage.