Since the current series was my first attempt at deconstructing the chemicals inside skin care products, I have been oscillating (going back and forth) with a given layout of the series. No, this is not your fault (the reader). I am just trying to find a way to simplify the series to illustrate the science behind such products and furthermore the ingredients within. The ultimate goal is to demystify the scams and myths behind 'anti-aging products' which seems to be growing toward an annual multi-billion dollar industry.
With that being said, to continue with the last post, I got caught up with a few of the ingredients having multiple functionalities listed like "Skin-conditioning agent" or "Absorbent". This led me to form the glossary below -- which I hope will shed light on the purpose of listing the functions of each chemical ingredients on websites like the "Environmental Working Group" which provide great (and detailed) information to the public.
To start with, I will proceed alphabetically. I will cover the terms listed as functions in the last post which can be found here.
From "The Free Dictionary.com" -- Absorbent: a substance that is capable of absorbing.
From "wikipedia" for 'Adhesive':
Adhesive may be used interchangeably with glue, cement, mucilage, or paste, and is any substance applied to one surface, or both surfaces, of two separate items that binds them together and resists their separation. Adjectives may be used in conjunction with the word "adhesive" to describe properties based on the substance's physical or chemical form, the type of materials joined, or conditions under which it is applied.The use of adhesives offers many advantages over binding techniques such as sewing, mechanical fastening, thermal bonding, etc. These include the ability to bind different materials together, to distribute stress more efficiently across the joint, the cost effectiveness of an easily mechanized process, an improvement in aesthetic design, and increased design flexibility. Disadvantages of adhesive use include decreased stability at high temperatures, relative weakness in bonding large objects with a small bonding surface area, and greater difficulty in separating objects during testing. Adhesives are typically organized by the method of adhesion. These are then organized into reactive and non-reactive adhesives, which refers to whether the adhesive chemically reacts in order to harden. Alternatively they can be organized by whether the raw stock is of natural or synthetic origin, or by their starting physical phase.
3) Anti-caking Agent:
From 'wikipedia' for 'Anti-caking Agent':
An anticaking agent is an additive placed in powdered or granulated materials, such as table salt or confectionaries to prevent the formation of lumps (caking) and for easing packaging, transport, and consumption.
Ex: a list of common 'anti-caking agents' (and articles) can be found here.
From 'wikipedia' for 'anti-foaming agent':
A defoamer or an anti-foaming agent is a chemical additive that reduces and hinders the formation of foam in industrial process liquids. The terms anti-foam agent and defoamer are often used interchangeably. Commonly used agents are insoluble oils, polydimethylsiloxanes and other silicones, certain alcohols, stearates and glycols. The additive is used to prevent formation of foam or is added to break a foam already formed.
From the website "Cosmetics and Skin.com" -- Binding Agents: binding agents such as gums, fats, or waxes which hold the product together.
From 'wikipedia' for 'buffering agent':
A buffering agent is a weak acid or base used to maintain the acidity (pH) of a solution near a chosen value after the addition of another acid or base. That is, the function of a buffering agent is to prevent a rapid change in pH when acids or bases are added to the solution. Buffering agents have variable properties—some are more soluble than others; some are acidic while others are basic. As pH managers, they are important in many chemical applications, including agriculture, food processing, biochemistry, medicine and photography.
From the website 'Cosmeticsinfo.org' -- Denaturant:
The process adds a small amount of a denaturant to the alcohol to make it taste bad, thus creating alcohol that is not suitable for drinking, but is otherwise similar for other purposes.
The definition of an 'Emollient' comes from 'wikipedia' for "Moisturizer":
Moisturizers or emollients are complex mixtures of chemical agents specially designed to make the external layers of the skin (epidermis) softer and more pliable. They increase the skin's hydration (water content) by reducing evaporation. Naturally occurring skin lipids and sterols, as well as artificial or natural oils, humectants, emollients, lubricants, etc., may be part of the composition of commercial skin moisturizers. They usually are available as commercial products for cosmetic and therapeutic uses, but can also be made at home using common pharmacy ingredients.
The range of properties causes formulation chemists to break down the definition further. Below is the list of definitions from the website "Chemists Corner" - taken directly from here:
Traditionally, emollients are considered ingredients which have smoothing or softening properties. They are put into formulas to provide moisturizing benefits and support a variety of conditioning claims. There are a number of types which we’ll list below.Hydrophilic emollientsThe term emollient is rather broad so things that are humectants can also be considered emollients. Water soluble ingredients like glycerin, sorbitol, and propylene glycol are all technically emollients. When you need conditioning, this are good ones for your water phase.Lipophilic emollientsThese are ingredients that are not soluble in water and make up the bulk of the available varieties of emollients. The one that you use depends on properties such as polarity, emolliency scores, spreading behavior, compatability with other ingredients, rheological behavior, and hydrolytic stability. This group can further be broken down by grouping them by their polairity.Non-polar: These are mostly derived from petroleum and include ingredients like mineral oil, Isoparaffin, and Isohexadecane.Polar: This includes a range of ingredients including materials such as natural oils (Jojoba oil, Olive oil, coconut oil), esters (Octyl Palmitate, Isopropyl stearate, Isopropyl palmitate) and alcohols (Octyl dodecanol).Silicone fluid emollientsThe final group is silicone fluids. They provide incredible levels of slickness and also feel light compared to lipophilic emollients. The most common ones used include Cyclomethicone and dimethicone. There are a number of varieties to choose from and each have different characteristics when it comes to viscosity, volatility, and ease of formulation.
9) Emulsifying Agent:
From the "UNC School of Pharmacy" -- Emulsifying Agent:
Emulsions are stabilized by adding an emulsifier or emulsifying agents. These agents have both a hydrophilic and a lipophilic part in their chemical structure. All emulsifying agents concentrate at and are adsorbed onto the oil:water interface to provide a protective barrier around the dispersed droplets. In addition to this protective barrier, emulsifiers stabilize the emulsion by reducing the interfacial tension of the system. Some agents enhance stability by imparting a charge on the droplet surface thus reducing the physical contact between the droplets and decreasing the potential for coalescence. Some commonly used emulsifying agents include tragacanth, sodium lauryl sulfate, sodium dioctyl sulfosuccinate, and polymers known as the Spans® and Tweens®.Emulsifying agents can be classified according to: 1) chemical structure; or 2) mechanism of action. Classes according to chemical structure are synthetic, natural, finely dispersed solids, and auxiliary agents. Classes according to mechanism of action are monomolecular, multimolecular, and solid particle films. Regardless of their classification, all emulsifying agents must be chemically stable in the system, inert and chemically non-reactive with other emulsion components, and nontoxic and nonirritant. They should also be reasonably odorless and not cost prohibitive.
10) Emulsion Stabilizing Agent:
From 'wikipedia' for 'emulsion stabilization using polyelectrolytes':
Polyelectrolytes are charged polymers capable of stabilizing (or destabilizing) colloidal emulsions through electrostatic interactions. Their effectiveness can be dependent on molecular weight, pH, solvent polarity, ionic strength, and the hydrophilic-lipophilic balance (HLB). Stabilized emulsions are useful in many industrial processes, including deflocculation, drug delivery, petroleum waste treatment, and food technology.
11) Foam Boosting Agent:
From 'wikipedia' for 'foam boosting agent':
A foaming agent is a material that facilitates formation of foam such as a surfactant or a blowing agent. A surfactant, when present in small amounts, reduces surface tension of a liquid (reduces the work needed to create the foam) or increases its colloidal stability by inhibiting coalescence of bubbles. A blowing agent is a gas that forms the gaseous part of the foam.
12) Film Forming Agent:
From 'Paula's Choice Skincare' for 'film-forming agents':
Large group of ingredients typically found in haircare products, but that also are widely used in skincare products, particularly moisturizers. Film-forming agents include PVP, acrylates, acrylamides, methacrylates, and various copolymers. When applied they leave a pliable, cohesive, and continuous covering over the hair or skin. The film has water-binding properties and leaves a smooth feel on skin. Film-forming agents can be weak skin sensitizers, but this almost always depends on the amount used; lower amounts generally are not problematic.
Additional definition -- 'wikipedia'
From 'Wikipedia' for 'humectant':
A humectant /hjuːˈmɛktənt/ is a hygroscopic substance used to keep things moist; it is the opposite of a desiccant. It is often a molecule with several hydrophilic groups, most often hydroxyl groups; however, amines and carboxyl groups, sometimes esterified, can be encountered as well (its affinity to form hydrogen bonds with molecules of water is the crucial trait). They are used in many products, including food, cosmetics, medicines and pesticides.A humectant attracts and retains the moisture in the air nearby via absorption, drawing the water vapor into or beneath the organism's or object's surface. By contrast, desiccants also attract ambient moisture, but adsorb—not absorb—it, by condensing the water vapor onto the surface, as a layer of film.When used as a food additive, a humectant has the effect of keeping the foodstuff moist.Humectants are sometimes used as a component of antistatic coatings for plastics.In pharmaceuticals and cosmetics, humectants can be used in topical dosage forms to increase the solubility of a chemical compound's active ingredients, increasing the active ingredients' ability to penetrate skin, or its activity time. This hydrating property can also be needed to counteract a dehydrating active ingredient (e.g., soaps, corticoids, and some alcohols), which is why humectants are common ingredients in a wide range of cosmetic and personal care products that make moisturization claims (e.g., hair conditioners, body lotions, face or body cleansers, lip balms, and eye creams).
14) Masking Agent:
From 'wikipedia' for 'masking agent':
A masking agent is a reagent used in chemical analysis which reacts with chemical species that may interfere in the analysis. In sports a masking agent is used to hide or prevent detection of a banned substance or illegal drug like anabolic steroids or stimulants.
--FDA : labeling cosmetics
--List of masking agents - 'thegoodscentscompany'
15) Occlusive Agent:
From the website "ChemistsCorner" - Occlusive Agent:
Occlusive agents increase moisture levels by providing a physical barrier to epidermal water loss. Ingredients with occlusive properties include petrolatum, waxes, oils, and silicones. Some occlusive agents like petrolatum can leave a heavy feel so they are often combined with other ingredients, like emollients, to improve consumer appeal.
Additional resources: here and here
16) Opacifying Agent:
From 'wikipedia' for Opacifier:
An opacifier is a substance added to a material in order to make the ensuing system opaque. An example of a chemical opacifier is titanium dioxide (TiO2), which is used to opacify ceramic glazes and milk glass; bone ash is also used. Opacifiers must have a refractive index (RI) substantially different from the system.
17) Refatting Agent:
From the website 'wiktionary' - Refatting Agent: The replenishment of lipids to the skin.
18) Skin-conditioning Agent:
From the website "MiMi beauty" - Skin Conditioning Agent:
A skin conditioning agent and an essential fatty acid that helps maintain optimal skin health and function. Lipid Organic products found in living systems that are insoluble in water, like fats. Cell membranes are made of lipids.
Additional resources: ChemistsCorner
19) Skin Protecting Agent (skin protectant):
From the website 'Walgreens' for Skin Protectants:
Remedy Dimethicone Skin Protectant provides a breathable barrier that protects against moisture. Also protects and helps relieve chapped or cracked skin. Protects against moisture loss. This product is equally intended for use as a long-lasting moisturizer.
From 'wikipedia' for Surfactant:
Surfactants are compounds that lower the surface tension (or interfacial tension) between two liquids or between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, foaming agents, and dispersants.
21) Surfactant-Solubilizing Agent:
See 'wikipedia' page for 'Surfactant'.
As you can see above, the functions are clarified by listing the definition of each. Although, there are some glossary terms that refer to multiple terms in the glossary itself. One example is a 'skin conditioning agent' -- an emollient, etc. We need to think critically about the purpose of having the ingredient inside of the formulation.
Furthermore, listed above are the functions of the ingredients. Lots of information have been left out. One important piece is the relative concentration of each chemical. Some companies do not list concentration to avoid duplication of their marketed project. In the next post, we will return to the last post and look further into the lotion "Jergen's Skin firming" lotion in more detail.
Until then, Have a great day.