Creative Developments (Cosmetics) Limited

Colour 2000

All those involved in international trade in cosmetics must have initially welcomed the U.S. FDA approach to harmonisation of colour nomenclature. It was proposed that the prefix FD&C or D&C be dropped and that colours would be named by their simple name with the colour index (C.I.) number in parenthesis. For example FD&C Blue No.1 becomes Blue 1 for the North American market and remains CI 42090 on European ingredient listing. However for products sold on both continents the FDA is prepared to accept Blue 1 (CI 42090). Unfortunately certain European countries cannot accept this compromise so dual labelling remains a problem. In the U.S.A. it is now correct to name the colours by their shade and number only but they must still conform to the FD&C or D&C specifications and be certified as so doing. In line with Europe there is no longer a requirement to name the metallic salt for lakes in the U.S.A. It should be noted that there is not an international list of approved colours and specifications and differences between Europe, the USA and Japan are still to be resolved.

Each year the pigment manufactures appear to launch brighter, cleaner, more intense colours, more glitters and more interference colours. The latest offerings from Merck and shown at In-cosmetics 2000 are the Colorona Glitter Colours in bordeaux, bronze, chameleon, copper and sienna. These brilliant pearl shades are very transparent with a glittery effect due to their large particle size of 20 – 150 microns. The interference range from the same company has been extended by the addition of Timiron Super in green, gold, red, blue, copper and violet and are claimed to give lift and depth to colour cosmetics and to produce interesting effects when used as a pearlising agent in foam baths, shampoos and shower gels. Timeron Snowflake MP-99 is a titanium-coated mica that combines opacity with lustre and sparkle. It is tin-free and accepted for cosmetic use worldwide.

Sicopearl Fantastico is the range name given to a new group of lustrous colour variable pigments from BASF. The pigments consist of three layers, a core of aluminium or iron oxide, a middle layer of silicon dioxide and a transparent outer coating of iron oxide. The shades of the colour variable pigments are determined by both the thickness and the composition of the layers and the colour effect is dependent on the angle of observation. Sicopearl Fantastico may be used alone or in conjunction with standard pigments to create a wide range of shades and colour effects. BASF also supplies high purity iron oxide pigments and publishes a useful guide to the purity requirements of the main cosmetic markets of the world. It also provides solubility and other data for cosmetic dyestuffs that show the effect of different pH, heat and light on their stability. Dye and pigment stability when exposed to sunlight can often be improved by incorporating UV absorbers. BASF supply the Uvinul grades of UV absorber and data is provided that shows the improvements that can be expected if the optimum absorber is incorporated into the formulation.

Sparkles and glitters find application in all types of cosmetic product, from shampoos and bathroom toiletries to lipsticks, eye shadows and nail enamels. Elizabeth Connock [REF 1] described the technical background to providing stable suspensions of particulate matter in a variety of cosmetic applications and further developed the theme in an aptly titled paper; Particularly Pretty Particulates [Ref 2] and A&E Connock supply an extensive range of such materials. Creation Coleurs supplies Creasparkles, which do not contain dyestuffs or pigments, relying instead on the optical effects of reflected and transmitted light through a multi-layered plastic film. The film is transparent, consists of more than one hundred layers of two or more different polymers yet is less than 30 microns thick. Hologram effects and gold and silver colours are available as well as the standard blue, green, yellow and red shades.

Bismuth oxychloride has improved beyond recognition since its introduction into cosmetics over thirty years ago. Two new grades from Merck are Biron LF-2000 that is described as a lustrous, light-stable version with excellent skin feel and Biron MTU, a transparent, matte variety with minimal oil-absorption properties so that it does not upset the balance in a lipstick and render it brittle. Recent introductions of Mearl pigments from Engelhard include a group of interference pigments called Desert Reflections plus Gleams of Gold, Pinpoints of Pearl, Rays of Red and Visions of Violet. Engelhard have published a brochure entitled Trends 2001 that shows some very innovative uses of colour cosmetics.

Shade may be the consumer’s first reason for choosing a decorative makeup product but skin feel and durability are important aspects that will determine repeat sales. Silicone compounds offer a means to improve both properties. Dow Corning offer DC 9506, a powdered dimethicone/vinyldimethicone crosspolymer that can be used to produce a cream-to-powder foundation that behaves and feels like a pressed powder but is in cream form. It also adds viscosity to w/o and w/Si formulations and to cyclomethicone and is said to impart a dry smoothness with a light powdery skin feel.

Whether to be decorative or used to enhance appearance most colour cosmetics are applied as a film. This may be a liquid film as with a fluid foundation, a film of powder as for eyeshadows, of oils and waxes as with lipstick or as a hard coating such as nail enamels. In many cases rendering the film waterproof is a desirable attribute. Syntran 5190 is an acrylates copolymer in low viscosity liquid form from Interpolymer Corporation that is recommended for improving pigment dispersion and that forms a waterproof and durable film.

CK Witco Specialty Silicones recently introduced Silsoft SurFace film former, a highly cross-linked dimethicone copolyol (INCI name: dimethicone copolyol polyacrylate), in a silicone-in-water emulsion system. Drying of the emulsion leaves a continuous, flexible film that confers water resistance to water-based formulations, while remaining easily removed with cleansing lotion. Because the Silsoft Surface film is also resistant to oil, cosmetic formulations are additionally resistant to sebum. The surfactant character of the polymer enables its aqueous emulsion to be added directly to the oil phase of lipsticks and it is said not to affect the appearance of the stick, which can still be flamed.

Pecosil DCU (INCI- Dimethicone Copolyol Undecylenate) from Pheonix Chemicals is a clear
liquid silicone ester that is miscible in both water and castor oil and functions as a water/ silicone-coupling agent. Ultrabee from Hansotech is dimethiconol beeswax that couples silicone derivatives with oils, fats and waxes and is particularly useful when creating kiss-proof lipsticks. Ultrabee WD is a water-dispersible version with applications in cosmetic emulsions. Gel Base BSM5 from Brooks Industries is a combination of a dimethicone polymer with phenyl trimethicone that forms a water and wear-resistant polymeric film on the skin. Its polymer content has an optically smoothing effect on fine lines and it may be readily incorporated into emulsion products making it ideal for foundations and liquid makeup.

The light-diffusing properties of certain polymers and modified pigments (LDP) has become a popular means of enhancing the skins’ appearance. Wrinkles on the skin are perceptible though the contrast of light and dark, which accentuates even very subtle creases. As light hits spherical LDP particles it is scattered, obscuring the perceived line between areas of light and dark on the skin. Cardre produces a number of LDPs based on PMMA beads with titanium dioxide or zinc oxide treated with alkyl silane. Cardre also offers PMMA that has been coated with surface-treated iron oxides, which provide colour with a smooth ball-bearing feel, are highly hydrophobic and very compatible with oils.

PMMA beads are a highly porous spherical polymethyl methacrylate that can be loaded with active ingredients to serve as a delivery system in cosmetic applications. Release of the active ingredients across the diffusion gradient occurs steadily as the make-up application is worn on the skin. The spherical nature of PMMA beads imparts a ball-bearing effect that is claimed to improve feel, spreadability, and wear of the final product. In lipsticks, PMMA beads reduce tackiness, liquid make-ups have improved feel and the flow characteristics of powder systems are improved while breakage in pressed powders is reduced.

Other examples of spherical particles for use in makeup applications are silicon resin spheres available from A&E Connock in 2, 3 and 4.5 micron sizes and polyethylene spheres from the same supplier. Rona offers Ronasphere LDP, silica spheres coated with titanium dioxide and iron oxide with light diffusing properties. Colour streaking is a problem caused by sebum production under makeup. Various means of reducing this are available: Sebumase is a magnesium aluminium silicate from Miyoshi Kasei that has exceptional sebum absorption capabilities and also confers a matt finish and it does not add viscosity to the product Skin Flow is an aluminium starch octenylsuccinate from Mid-West Grain Products and similar materials are available under the Dry-Flo name from National Starch. They reduce oiliness and improve the flow and skin feel characteristics of powders and liquid makeup.

Spherical beads of magnesium silicate are available from 3M as CM 111 and Cardre have further improved their characteristics by surface treatment. Alkyl silane is used as a hydrophobic coating and to improve dispersion in oils. Phopholipids and lauroyl lysine are each used to improve skin feel and metal soaps to improve compression characteristics and skin adhesion for pressed powders. A novel process offered by Cardre is the use of flower waxes to surface-treat pigments. The waxes are extracted from the flowers of lavender, sage and chamomile and are said to improve application, adhesion and wear properties of pressed powder products. The wax coating acts as a barrier between the skin and pigment, preventing the dry feeling that many users experience with pigmented products.

Surface-treatment of powders has transformed the quality of makeup over the past decade and many different ones are available. Recently introduced are ST 25 hydrophilic iron oxide pigments from Whittaker, Clark & Daniels that are treated with galactoarabinan, a naturally derived polysaccharide from trees. It is hydrophilic; it improves pigment dispersion and product stability and has a moisturising effect on the skin. Other treatments from the same company include magnesium myristate as an alternative to silicones for hydrophobic properties, teflon for smoothness and water repellency and sodium PCA for moisturising properties. St-Pegmod from US Cosmetics Corporation is a dimethicone/glyceryl rosinate/octyldodecyl myristate hydrophobic treatment for iron oxides and organic pigments. Other surface treatments were covered extensively in previous issues of Manufacturing Chemist [Ref 3].

Finally wearing a film of makeup on the skin all day can become quite uncomfortable, I am told. Incorporating Questice from Quest International gives it a light refreshing coolness while Soothex has a skin-calming action to reduce irritation effects.

The addresses of the ingredient suppliers mentioned in the text with their British and world-wide distributors may be found in the CTMS Directory etc.

Ref 1 Connock, E., Physical Exfoliants, Cosmetics & Toiletries Manufacture Worldwide 1999, Aston Publishing Group.

Ref 2 Connock, E., Particularly Pretty Particulates, Cosmetics & Toiletries Manufacture Worldwide 2000, Aston Publishing Group.

Ref 3 Woodruff J, Colour Innovations aid the Formulator, Manufacturing Chemist, June 1998.