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Esthetics

Learn about basic procedures and applications of esthetics

The Chemistry of Lipstick

Cosmetic Chemistry – The Chemistry of Moisturisers

Definitions

Cosmetic Ingredient Definitions

Types of ingredients:

Functional ingredients - allows the product to spread, gives body and texture to the product and gives it a specific form. Necessary to the product formulation but does NOT affect the skin. Example - preservatives

Performance ingredients - affects the skin. Can be referred to as 'active ingredients.'

Delivery Systems - chemical systems that deliver ingredients to specific tissues of the epidermis.

Vehicles - spreading agents and carrying bases. These are necessary to the formation of a cosmetic (functional ingredients). 

Liposomes - closed lipid bilayer spheres that encapsulate ingredients and target their delivery to specific tissues of the skin. 

Polymers - chemical compounds formed by small molecules. These are advanced vehicles and release substances into the skin's surface at a controlled rate. 

Product Ingredients:

water- vehicle and performance ingredient. Replenishes moisture in the skin and helps keep other ingredients spread on the skin. 

Anhydrous - Products that do not contain water. Ex: oil serums, lip balms, silicone serums. Usually designed for dry skin.

Emollients - fatty materials that lubricate and moisturize the skin. Can help spread product and serve a purpose as a performance ingredient. They prevent dehydration by trapping water and decreasing transepidermal water loss. Emollients can cause or worsen development of comedones. Comedogenicity - tendency of a topical substance to cause or worsen a buildup of dead cells in the follicle. Can lead to the development of a comedo.  

Types of Emollients:

Oils from the Earth - protection against dehydration, prevent irritant skin contact, can be combined with water and blended into a cream. Can be used with no added preservatives. Do not harbor bacteria or other organisms. Act as a lubricant. Examples - mineral oil, petrolatum

Oils from Plants - contain fatty acids, prevent skin dehydration. Examples - coconut oil, palm oil, safflower oil, sunflower oil, canola oil, jojoba oil

Fatty Acids - lubricant ingredients from plant oils or animal fats. Not irritating. Examples: oleic acid, stearic acid, caprylic acid

Fatty Alcohols - fatty acids that have been exposed to hydrogen. Not drying. Have a wax-like consistency and can also be used as a spreading ingredient. Examples - cetyl alcohol, lauryl alcohol, stearyl alcohol 

Silicones - oils that are chemically combined with silicone and oxygen. These leave a noncomedogenic protective film on the surface of the skin. Also act as a vehicle in some products (such as foundation). Used as protectants. Examples: dimethicone, Cyclomethicone, phenyl trimethicon; found in sunscreens, foundations, moisturizers. 

Surfactants - reduce surface tension between skin and the product. Increase spreadability of cosmetic products

Detergents - reduce surface tension of dirt and oil on the skin's surface and form an emulsion to lift dirt and oil from skin. Cause foaming in cleansers. Examples - sodium lauryl sulfate, sodium laureth sulfate, ammonium lauryl sulfate. 

Cleansers - Detergents that clean the skin.

Emulsifiers - surfactants that make water and oil mix together. These surround oil particles and allow them to be evenly distributed into a product as opposed to separating into layers

Oil Soluble - substances that are compatible with oil and are therefore mixed in with the oil in the product's manufacturing.

Water soluble - substances that are compatible with water and are mixed with the water phase of manufacturing. 

Gellants and Thickeners - used to give the product a gel-like consistency. Example - Carbomers (used to thicken creams and are often used in gel products)

Fragrances - give the product a scent. Examples - plant oils, essential oils.

The practice of using different fragrances, particularly essential oils and plant aromas for therapeutic purposes is called aromatherapy.

Preservatives - prevent bacteria and other microorganism from living in the product and becoming contaminated. Can also prevent adverse chemical changes to a product. Examples - parabens, quaternium 15, urea.

Chelating agent - chemical added to cosmetics to improve the efficiency of the added preservative. Break down the cell walls of bacteria and other microorganisms, thus destroying them. Examples - disodium EDTA, trisodium EDTA, tetrasodium EDTA

Antioxidants - used as a preservative as well as an ingredient to condition the skin. Stops the oxidation process that can cause a product to spoil. 

Color Agents - add color to the product to enhance the visual appeal. In cosmetics, these are what gives the color to products like foundations, lipsticks, and eye shadows. Examples - dyes such as vegetable, pigment, and mineral

Certified colors - synthetic, inorganic colorants. Also known as metal salts. Batch certified and approved by the FDA.

Noncertified colors - organic, less irritating, and useful for cosmetics used around the eye areas. 

Lakes - insoluble pigments made from combining a dye with an inorganic material. 

pH adjustors - can be acids or alkalis (bases) and are used to adjust the pH level of products. Examples - sodium hydroxide, citric acid.

Solvents - dissolve other ingredients. Examples - water, alcohol.

Botanicals - ingredients that come from plants.

Healing agents - ingredients added to heal the skin. Examples - chamomile, licorice, azulene, aloe.

Hydrators (or humectants) - ingredients that attract water to the skin's surface. Can lock water on the skin to improve dehydration. Examples - glycerin, sodium PCA, sorbital, seaweed extracts, algae extract, hyaluronic acid, propylene glycol. 

Moisturizers - most are a combination of emollients and humectants.

Lipids - improves the barrier function of the skin to enhance hydration, plumpness and smoothness of the skin. 

Exfoliating ingredients - ingredients used for the removal of deal corneum cells. 

Mechanical exfoliants - added to products to physically scrape skin to remove the dead cells. Examples - jojoba beads, ground nuts.

Chemical exfoliants - loosen the bond between cells in the surface of the corneum. Can also lighten pigmentation and soften rough skin. Examples - Alpha hydroxy acids (AHAs), beta hydroxy acids (BHAs).

Enzymes - dissolve keratin proteins on the surface of the skin. Examples - papain, bromelain, pancreatin 

Lighteners and Brighteners - ingredients that "lift" a dark pigmented area to a lighter color. They work by either bleaching the upper layer of the epidermis or by slowing down the pigment factories in the skin and blocking melanin production. Examples - hydroquinone, kojuc acid, arbutin, vitamin C, licorice root, bearberry, green tea extract, alpha hydroxy and beta hydroxy acids. 

Ingredients that improve Cell Metabolism and Oxygenation - ingredients that emulate younger skin and can slow the appearance of aging. 

Antioxidants - neutralize free radicals before they can destroy cells. Are also preservatives added to prevent oxidation of a product. Examples - Vitamins C and E, green tea, DMAE.

Polyglucans and beta-glucans - believed to strengthen immune cells. Polyglucans are hydrophilic and help preserve and protect collagen and elastin. Beta-glucans help reduce the appearance of fine lines and wrinkles by stimulating collagen formation. 

Tissue respiratory factor (TRF) - derived from yeast cells. An anti-inflammatory and moisturizing agent. 

Glycoproteins - enhance cell metabolism and boosts oxygen uptake in the cell. 

Peptides and Collagen Stimulants ; Peptides - amino acid chains to produce changes in the skin's appearance. Can stimulate the fibroblasts (cells that produce collagen) to improve firmness and soften wrinkles. Examples - palmitoyl pentapeptide-3, palmitoyl oligopeptide. 

Retinol - stimulates cell repair and generates new cells. 

Coenzyme Q10 - protects and revitalizes skin cells. An antioxidant. 

Vitamin K - used for blood coagulation.

 

Gerson, J. (2009). Skin care products: chemistry, ingredients and selection. In Milady's standard esthetics: Fundamentals (pp. 252-293). Cengage Learning.