Active Ingredient:
The element of a topical agent which has a specific action useful in treatment of a skin disorder.
AHA:
Alpha-Hydroxy Acid. Used at lower concentration, these acids moisturize and increase skin’s suppleness. Used at higher concentrations, they exfoliate thus stimulating epidermis renewal.
Allergen:
Foreign substances that can produce a hyper-sensitive reaction.
Allergy:
An inappropriate reaction of the body’s immune system to an intrinsically harmless antigen. Also referred to as a ‘hyper-sensibility’ reaction.
Amino Acids:
The building blocks of protein. These acids are essential for cell life. They also help to keep moisture in the skin.
Anti-Free Radicals:
Anti-aging agent. Substances which trap free radicals and prevent their harmful effects. (for example, Vitamin E, flavonoids…)
Astringent:
A substance that causes skin contraction of the skin tissue, used in some fresheners to tighten pores.
Basal Layer:
The layer in the skin where new epidermal cells are produced.
Cellulose:
Main constituent of plant cell walls. It’s a fibrous material.
Cinnamates:
Chemical sunscreen which absorbs UVB rays.
Collagen:
Fibrous protein which is responsible for the skin’s firmness.
Comedones:
The correct word for blackheads. Formed when keratinised cells become trapped in the pores of the skin and build up, preventing sebum from flowing onto the skin’s surface.
Ceramides:
Lipids contained in the hydrolipidic film and between cells (intracellular cement) of the stratum corneum. Participate in skin barrier function.
Contact Dermatitis:
An inflammatory reaction of the skin to an outside agent. In can affect numerous area of the body and vary widely in severity.
Cream:
A semi-solid emulsion of oil-in-water.
Dermatitis Inflammation:
General term used to describe superficial inflammation of the skin. May be referred to as eczema.
Dermatologically Tested:
Indicates that the finished product has been tested by a dermatologist on human volunteers for signs of irritancy.
Dermis:
The layer of skin between the epidermis and the subcutaneous tissue. Contains blood vessels, lymphatic vessels and nerve endings.
Eczema:
General term used to describe superficial inflammation of the skin. May be referred to as dermatitis.
Elastase:
A destructive enzyme which breaks down the skin’s natural elasticity (elastin).
Elastin:
Protein responsible for the elasticity of the skin.
Emollient:
A softening and soothing agent.
Emulsifiers:
An ingredient that combines oil and water together to produce an emulsion. Also used as a cleaning agent as it lifts oil and impurities from the skin.
Exfoliator:
Substance which eliminates dead cells of the horny layer.
Epidermis:
The avascular outer layer of skin.
Erythema:
Redness of skin.
Fibroblasts:
Cells located in the dermis, responsible for collagen and elastin synthesis.
Free-radicals:
Reactive and non-stable molecules. React with all cells’ components.
Gel:
A colourless, transparent, semi-solid emulsion which liquefies on contact with the skin and dries to a thin, greaseless, non-staining, non-occlusive film
Glycerin:
Denaturant; skin conditioning agent/humectant; viscosity decreasing agent; humectant; also an active ingredient in OTC products.
Humectant:
Enhances the water-bearing capacity of the stratum corneum and holds water in the skin for prolonged times. A very good ingredient in a moisturizer.
Hydro-lipidic Film:
The skin’s natural protective barrier. Consists of sebum from the sebaceous gland and water. Has a pH of 5.5, which makes the skin slightly acidic.
Keratinocytes:
Cells located in the deepest layer of the epidermis while transforming from the horny layer.
Liposomes:
Tiny fatty spheres consisting of a double layer membrane which encloses a water containing compartment. This acts as a delivery system to improve absorption of water soluble ingredients in the skin.
Lotion:
Topical preparation that usually consists of a powder suspended in water, but can have a liquid composition. A lotion provides a protective, drying and cooling effect.
Melanin:
A natural pigment produced by melanocytes stimulated by UV light. As the melanin rises to the surface, it helps to protect from further damage and gives the skin its tan.
Mineral Pigment:
Non-reactive inert substance that is opaque and reflects light. A good example is titanium dioxide. This is used in total sunblocks as a white colourant.
Melanocytes:
Dendritic cells located in the basal cell layer.
NMF:
Natural Moisturizing Factor. Hydroscopic molecules which keep water in the skin.
pH:
Measure of alkalinity or acidity. Water is 7 (neutral), skin is 5.5 (slightly acidic) and soap is 10 (alkaline).
Psoriasis:
A chronic skin disease characterized by rapid replication of epidermal cells.
Scale:
A flake of cells loosened from the stratum corneum.
Sebaceous Glands:
Glands connected to hair follicles by tiny ducts. Sebaceous glands secrete a substance called sebum, which lubricates the hair and skin.
Stratum Corneum:
The most superficial part of the epidermis, made of 8 or 10 layers of flat cells linked together by an extra-cellular cement. Barrier role against dehydration, prevents foreign substances and micro-organisms penetration.
Sweat Gland:
Glands which secrete a thin, saline fluid and play an important part in regulation body temperature through evaporation.
Ultraviolet Light:
Light waves classified by length. Long-wave ultraviolet light is called UV-A. Middle-wave ultraviolet light is called UV-B and causes tanning and burning. UV-C is short-wave ultraviolet light.
Vitamin A:
Essential to the skin’s functions. Stimulates cell renewal. Improves the skin’s suppleness and cohesion.
Vitamin E:
An anti-oxidant that will neutralize free radical damage.
W/O Emulsion:
Water-in-oil mixture where fine droplets of water are dispersed in an oily phase.
Xerosis:
Dry Skin; a common coetaneous disorder with superficial scaling; usually most prominent on legs; more common in the elderly.