You are a new marketing associate participating in your company’s weekly development status meeting when the R&D representative says, “We added Ingredient X to the emulsion and it cracked.” “Huh?” you say. “Emulsion? cracked?” You mumble to yourself: “I thought we were talking about a lotion. What do these words mean?”
A difference in marketing and R&D jargon often causes confusion and apprehension when these different departments communicate with each other. This article, part one of two, seeks to provide some general understanding of what the R&D group is referring to during these interactions. This is designed to serve as a primer for new marketing associates and help in reduce the “push-pull” syndrome found in many, many organizations.
Emulsions: Yes, We’re Talking About Lotion
Before exploring other components of skin care and the finer points of basic beauty product types, let’s discuss emulsions. Used to formulate many beauty products, emulsions are mainly used for the preparation of creams and lotions. Basically, they are mixtures of oil and water. And despite what you may think (oil and water don’t mix), there are amazing ingredients called emulsifying agents that hold the two together. When mixing the oil and water together, the oil forms little droplets in the water. When you stop shaking, the oil droplets come together (coalesce) and rise to the surface. With the addition of the emulsifying agent, the oil will remain as discrete droplets. The emulsifier positions itself between the surface of the oil droplets and the body of the water. This maintains the homogeneity. When the oil forms the droplets in the water, it is an oil-in-water emulsion (o/w ). The reverse is a water-in-oil emulsion (w/o) Because oil and water are clear and a lotion or cream is opaque, it warrants a brief (very brief, don’t worry) discussion of the principles of light transmission. When light strikes a clear material, oil or water, it passes through. The eye sees this as a clear liquid. When there are droplets of one liquid in another, the light bounces off the droplets (like a pinball) and does not pass through, creating an opaque effect.
Therefore, what your eye sees is no longer a clear liquid.
Why use an emulsion? It is a means of delivering performance ingredients that are not water-soluble. These can be emollients, moisturizing agents, vitamins, thickeners for the formula, etc. Emulsions also provide a more aesthetically pleasing product—no greasy residue on the skin, for example. The water phase can contain herbal extracts, film formers, water-soluble moisturizers, etc. Emulsions can be used to formulate creams, lotions, spray lotions and thin liquids, among other product types—and can be used as formulation platforms for: skin treatment products, fragrance line extensions, massage treatment, sun protection, etc. In color cosmetics, an emulsion is a suitable delivery system for liquid and creamy foundations.
One further note: The “cracked” term used for emulsions simply means that the cream or lotion has separated into distinct layers. It is no longer homogeneous.
Components of Skin Care Products
Now, here are a few types of materials that can be delivered through emulsion systems. Emollients: These are added to provide a skin-softening effect. Chemically, they are esters that can be modified to vary the feel on the skin. Those that have a “dry” feel have virtually no perceptible feel on the skin. Those with a “wet” or “oily” feel leave a noticeable residual on the skin.
Exfoliants: These are included in skin care formulas to remove the uppermost layer of dead cells. They provide for the newer “more alive” cells to be at the surface. They also impart a glow to the skin.
Exfoliation can be done in either of two ways: mechanical and chemical. The mechanical method physically abrades away dead cells. Ingredients for this purpose include ground walnut shells, beads of jojoba wax (which can also melt onto the skin to provide emolliency) and plastic spheres of polyethylene or nylon. Chemical exfoliants perform by reacting with the dead, upper layer skin cells. This causes the cells to become unglued and slough off. Ingredients for this purpose include: alpha-hydroxy acids (AHAs) such as glycolic acid and fruit acids. Beta-hydroxy acids (BHAs) are also chemical exfoliants and include salicylic acid and willow bark extract (which contains salicylic acid), and these are very effective. Note, when AHAs are included in a formula, there needs to be an advisory label cautioning about exposure to the sun. In addition, there needs to be an effective sunscreen present in the formula.
Sunscreens protect the skin from the harmful effects of ultraviolet (UV) rays. There are two UV ranges of wavelengths that cause problems: UVB causes stimulation of melanin to induce tanning, but also causes burning. UVA penetrates more deeply into skin tissues, and these rays are involved in the destruction of DNA and breakdown of cell structure via free radical release, causing the appearance of premature aging and wrinkling.
There are two types of protection mechanisms: organic sunscreens and inorganic (physical) sunscreens. The organic sunscreens function by having the chemical molecules absorb the UV energy before it reaches the skin. The inorganic types function by reflecting the sun’s rays away from the skin. The original inorganic sunscreens produced the familiar opaque, white “lifeguard nose” effect. New technology has reduced the size of the particle so that it appears to be transparent. Remember, there are no chemical-free sunscreens—only organic and inorganic ones.
A Look at Other Product Types
Bath and Body. Bar soaps are formed by reacting animal fatty acids or vegetable oil fatty acids with lye, also known as sodium hydroxide. Once the reaction is complete, the lye (also used in drain cleaners, concrete, etc.) is no longer harmful. Soap is an effective cleaner, but will also strip natural sebum deposits from the skin, causing dryness. Various additives— such as fragrance, moisturizers and mechanical exfoliators—can be included in a soap formula. Per U.S. Food & Drug Administration classifications, plain soap (with no additives) is not classified as a cosmetic, and need not contain an ingredient list.
So, how does a chemical mass become a bar of soap? In mass-produced soap, once the chemical reaction is complete, little gnome like artisans carefully carve the hardened mass into the soap bar shapes that are easily recognized ... well, not quite, but chemists are allowed to have a sense of humor. Actually, the mass, while still soft and pliable, is forced through an extruder—quite like the way pasta is formed. After cutting to the proper size, these “noodles” are blended with the proper additives and fed into a press whose die mold is in the shape of the soap bar. Once pressed, the bar is ready for its final steps of packaging. Shower gels are detergent systems that provide an enriched body cleansing experience. The use of detergents makes them immune to the effects of hard water—the loss of foaming effect and production of soap scum on shower/bath stalls. The detergents are modified to reduce irritation while still providing a rich foam, and special thickeners are added to produce the gel. It is the skill and knowledge of the formulating chemist that provides for the proper consistency without being gooey and slimy. Technically similar products include foaming facial cleansers and liquid hand soaps Powdered bubble bath products develop a higher foam. Often water softening additives are included to give a “silky” bathing experience.
Hair Care. In shampoo, the detergent type and foam stabilizers are fine-tuned to provide both an effective and aesthetically pleasing hair cleansing system. A rich and billowy foam is best for a luxurious feel. A tight foam (small, closely packed bubbles) is preferred for a shower gel/shower cream, while a loose and lacy foam is desired for a facial cleanser. The detergent ingredient in shampoos is selected for its foam qualities as well as for its mildness properties.
In hair care, soap is not recommended. Issues with hard water will eliminate the desired foam quality and leave a dulling film deposit on the hair.
Conditioners utilize technology adopted from the textile industry. The conditioning agents work with the electrical charge on the hair, and the conditioning molecule has a “charged” end and a “lubricating” end. The charged portion attaches to the hair (which has an opposite charge) while the lubricating tail of the molecule allows one hair fiber to “slip” over the others.
Styling aids are often used to add body to the hair to hold it in position. These use film-formers to cast a film on the hair, which, upon drying, hold the hair style in place. The film-former is selected based on the required properties: firm hold, medium hold or loose hold.
Makeup. Under makeup moisturizers provide a smooth base for makeup application. These formulations are based on emulsion technology. Newer products include a sunscreen as daily, non-beach, protection from the sun. The technical challenge is that the sunscreen systems must absorb into the skin quickly, with no residual “glow” on the skin. However, the organic sunscreens are oily in nature, which will impart a glow. It is the chemist’s creativity, at this point, to find the proper blend of ingredients to provide for sun protection yet not leave a shine on the skin.
Pressed powder delivers a tint to the skin while smoothing skin appearance. These products consist of talc, colorants and a “binder.” Other materials may be present, but these are the core items. One technical challenge is to deliver the colorant in a way that it is uniform throughout the batch, without little spots of pigment agglomerate. This is achieved by making a color concentrate. Here, the dry powdered pigments are blended with a small amount of the talc. This mixture is placed in a mill where rotating metal bars break the powder blend into fine particles. This is the pigment concentrate that is then mixed with the remainder of the talc and binder. The powder is then filled into the pan, and a press is used to compress the powder. The binder’s function here is to hold the particles together in the pan.
Lipstick formulas are a blend of waxes, oils and pigments. The blend of the proper waxes and oils will dictate whether there is a stick firm enough not to melt in one’s handbag, flexible enough not to break during application, smooth enough to provide a uniform application and contain sufficient oils so as to not feel too dry on the lips. The pigments, which are supplied in powder form, must be processed to get them to a uniform and very fine state so there are no “hot spots” of color agglomerates. To achieve color uniformity the pigment powders are mixed with a small amount of the oils—often castor oil is used. This liquid blend is passed through a roller mill that reduces the size of the pigment particles in the oil. The milling continues until there are no longer any particles visible by instrumental testing. This concentrate is then blended with the rest of the oils and waxes, which have been heated until they have liquefied. The melt is mixed until uniform. It is then poured into individual molds in the lipstick shape. To accelerate the process, the molds are then placed in a cold room or cooling tunnel. When sufficiently cool and firm, they are inserted into the lipstick case.
Glitter ingredients for eye shadow develop color (and color change) on the lid when light strikes the color particles, which are sandwiches of colorants and mica in small particle size. Creamy eye shadow uses emulsion technology, and powdered eye shadow uses pressed powder technology.
Mascara uses pigments and film formers to lay down a coating on the lash. As the coating dries, it leaves a pigmented film which gives increased body and length to the lash.
Hopefully, this article has given you a bit of an insight into some of the formula types that you will be working on. With this understanding, the relationship with the R&D function will be a little smoother.
Watch for Part II: “Why Does R&D Always Say ‘Not Ready Yet’?”
Art Rich, PhD, is a member of the GCI magazine editorial advisory board. In addition, he is founder and chief consultant at A. Rich Development, LLC., which was founded in 2001. Rich has more than 30 years of experience in the development of marketable personal care and cosmetic formulas for such companies as Johnson & Johnson, Avon, and Bath & Body Works. He can be reached at firstname.lastname@example.org.