John Woodruff reports on his selection of the SCS Formulate 2008 technical papers
The Tech Focus presentations at SCS Formulate are 20 minute sessions wherein suppliers describe their latest ingredients, their properties and their possible applications. These run concurrently with the show and the more in-depth seminars addressing particular aspects of cosmetic science so the problem inevitably arises as to whether be in the exhibition, the seminar or either of the Tech Focus presentations. What follows is the author’s choice of Tech Focus presentations, which largely reflect his current interests in product formulation.
PRESERVATION AND BEYOND
Preservation is such an important and difficult part of cosmetic formulation that choice of preservative system should be one of the first steps in developing a new product. Preservative selection was the subject of Developing the Preservation Paradigm given by John Hibbs (McIntyre Group). At one time adding an excess of formaldehyde was sufficient, then less formaldehyde, then formaldehyde donors, parabens IPBC or halogenated compounds were used but efficacy, regulations and consumer perceptions have made the subject increasingly difficult. Hibbs proposed an approach that put preservation at the heart of the development process by incorporating multiple actives to impart a multifunctional and holistic approach to formulation.
This has resulted in three different materials by McIntyre. Phenagon PBD is based on a combination of phenoxyethanol, benzoic acid and dehydroacetic acid that provides broad range protection against gram positive/negative bacteria as well as yeasts and moulds when used below pH 6.0. Mackstat GCM exploits the synergy between functional and traditional preservatives by combining methylisothiazolinone with glyceryl caprylate, an antimicrobial emollient. Mackaderm GCP comprises functional ingredients with secondary antimicrobial properties to give resistant formulations. It is a combination of glyceryl caprylate with phenethyl alcohol, a fragrance compound that makes it possible to make preservative-free claims.
Ongoing public discussions about preservative actives and the increasing demands of marketing make it more important than ever to find ways to improve the efficacy of traditional preservatives. Boosting efficacy of preservatives was the title of the presentation by Christine Oleschkowitz (Shülke & Mayr) which described the enhancement effect of 0.1% ethylhexyl glycerin on the preservation efficacy of phenoxyethanol, methylisothiazolinone and methylparaben. Single actives failed a challenge test after two inoculation cycles but the addition of ethylhexyl glycerin ensured they all passed. Oleschkowitz then described the further enhancement obtained by using chelating agents in combination with phenoxyethanol/ethylhexyl glycerin. Noticeably, tetrasodium dicarboxymethyl glutamate in combination with citric acid gives a substantially better effect than can be achieved with any of the other combinations tested.
Presentations on preservatives were also given by Graham Lawson (Thor Specialities), who described new preservative systems for personal care applications, and Henk de Jager (Jan Dekker International) with the title Preserving appearances – a user’s guide to acceptable preservation. Fakhara Jones (Surfachem) described a naturally occurring antioxidant and free radical scavenger with considerable antimicrobial properties based on ligands from trees.
TRENDS TO WATCH
A regular feature at Formulate and guaranteed to fill the lecture theatre is the trends presentation by Pauline Ayres (S. Black). Ayres first identified the trends in the main sectors of the personal care industry and then described some of the new materials offered by S. Black to meet those trends. The presentation was quick-fire with lots of bullet points as a subject worth two hours was squeezed into 20 minutes. Decorative cosmetics now include UV protection, anti-ageing claims and moisturising properties delivered from milder formulations. Hair products also make anti-ageing claims plus those against hair dullness and hair loss, scalp disorders and dandruff. Moisturising continues to be the top claim for skin care products with male skin care, improved radiance and anti-ageing very popular. All sectors show strong interest in natural, organic and ethical claims.
Ecocert or organic is a major theme across the whole industry but ingredients that enable the production of organic or Ecocert colour cosmetics have been sadly missing until recently, said Ayres. However the SunPURO range from Sun Chemical comprise ultra pure grades of iron oxides and titanium dioxide with Ecocert approval and approval has also been obtained for pearls, including some of the bismuth oxychlorides in the Biron range, some of the Coloronas and Timirons and Xirona La Rouge from Merck.
Other colours were described for their special effects and Eusolex T-PRO was suggested as a UV absorber for decorative cosmetics. It is magnesium and silica treated microfine TiO2 that is close to the colour of Caucasian skin. There were many other new and novel ingredients described to fulfil current interest including a number of cationic polymers obtained by the quaternisation of guar gum available as Esaflors; Vecorextin Protective, a liposomal delivery system designed to penetrate the hair shaft; and various conditioning agents from Inolex.
ACTIVE DELIVERY
Deliveries of actives by Rovisomes were also mentioned and these were the subject of a talk by Jennifer Skinner (Rovi Cosmetics). Rovisomes are microscopically small liposomes comprising a double layer around an aqueous core. They are produced from phospholipids with 80% phosphatidylcholine content. They are stable in final formulations, can decrease the irritancy of actives and can be filled with water or oil soluble actives, or both. The delivery of different actives by various Rovi systems was described. Examples include Rovisome Coenzyme Q10, said to support the energy supply of the cell metabolism; Cerasome Oxygen, said to increase the level of molecular oxygen in the deeper skin layers; and Genu pHresh, a polysaccharide extracted from citrus peel to help the skin maintain its acid mantle.
Delivery systems were also the subject of the presentation by Sam Shaeffer (Salvona Technologies) on how to create aesthetic and effective skin moisturising treatments. Shaeffer described the main causes of skin dryness as age, medication, diet and environment and said that conventional therapies based on emollients to reduce TEWL and humectants to hold water on the skin surface only last for about one hour. Salspheres from Salvona are a delivery system composed of hyaluronic acid, ceramides, glycerin and botanical extracts that work synergistically to repair the skin cellular barriers and capture moisture. They comprise a central core of a natural wax such as shea butter that is infused with glycerin and encapsulated in a polymer that retains water. On application to the skin the matrix breaks down to deliver the moisturising active over a sustained period. Various combinations targeted at specific needs are available under the SalSphere and MultiSal trade names.
SKIN CARE CONCEPTS
Skin care products are either designed to strengthen the skin barrier properties to protect it from environmental problems or to penetrate it to deliver active ingredients to where most needed. Skin barrier restructuring properties of emulsions created by an innovative liquid crystal system was the subject of the presentation by Carla Filippini (B&T) who described Olivem 1000 as a biometric restructuring agent. This Ecocert approved emulsifier is based on olive oil and is a combination of cetearyl olivate with sorbitan olivate. It is very compatible with skin lipids and forms liquid crystal structures that physiologically integrate with the upper layers of the stratum corneum and reduce TEWL.
Continuing the skin care theme Ken Jones (Sochibo) described Dextralip 10C as a proven cosmetic ingredient from France. This is sodium dextran sulphate, which has a long history of safe use in pharmaceutical preparations where it is used to reduce oedema and abscesses. It has now been shown to reduce inflammatory responses and to boost the activity of various actives in cosmetic applications. The material is a water-soluble polysaccharide obtained by bio-fermentation and is recommended for use at 0.2% to 0.5% in sun care, after-sun and slimming products as well as for combating pollution and oxidative stress.
An important focus of Formulate is on trends in cosmetics and ingredient suppliers often lead those trends by offering new materials, technological advances and new ideas for formulations. This was the subject of the presentation by Estelle Chevreton (Aston Chemicals) who introduced natural, functional and innovative ingredients for skin care, hair care and colour cosmetics. It was well illustrated with example formulations, which included a cleansing gel that melted on the skin and a cushioning night cream. This had a buttery texture combining the expected richness of an intensive treatment cream and the sensory properties associated with a product that delivers intense moisturisation, without leaving an undesirable oily-greasy film on the skin. For hair care Chevreton suggested a high gloss moisturising shampoo that incorporated olive oil and shea butter derivatives; materials that were also featured in a high gloss conditioner. Dipentaerythrityl pentaisononanoate is a shiny, non sticky, viscous ester with film forming properties that was proposed as the basis for a long-lasting lip gloss.
NATURAL EXTENSIONS
Natural materials continue to excite the cosmetic world and there were various presentations featuring these. Natural aromatics for personal care were described by Ed Matson (Carrubba). There is a definition of natural aromatics published by IFRA, which states that they are made by physically extracting the volatile fractions from plants without chemically altering them. Matson explained that a volatile oil is normally produced by steam distillation of vegetable plant matter and maintains the characteristic odour or flavour of the plant. Some botanicals such as citrus peel oils must be mechanically cold-pressed or expressed from the rinds of citrus fruits due to heat sensitivity. At Carrubba essential oils, oleoresins, distillates, fractions, concretes and absolutes are used to create complex fragrance compounds made exclusively from natural aromatics as defined by IFRA.
Emulsifying or solubilising natural oils can be a particular problem but Barrie Shelmerdine (McIntyre Group) presented a novel microemulsion approach to the formulation of essential oils, antioxidants and fragrances. Microemulsions form spontaneously without the need for high input of energy and are therefore easy to prepare. They are thermodynamically stable and can have a relatively low viscosity, making them suitable for spray applications as well as traditional delivery systems.
Shelmerdine described the different types of microemulsion and the use of phase diagrams to produce clear or translucent products by altering the ratios of oils, surfactants and salt in aqueous solution. Based on this technology McIntyre produces Mackerderm Clear Express, a blend of PEG-6 caprylic/capric glycerides with polyglycerol-6 dioleate and caprylic/capric glycerides to which may be added the natural oil and it is then stirred into water to produce a clear microemulsion. Other oil-based actives including oil-soluble vitamins and sunscreens can also be handled in a similar fashion.
Returning to the natural theme Andrea Tomlinson (Cognis UK) presented green raw material and formulation concepts for the natural market, David Anderson (Colonial Chemical) provided green surfactant solutions, Tim Meadows (Concentrated Aloe Corporation) described the applications and functions of tamanu oil in skin care products and Michael Schuricht (Symrise) offered natural botanical extracts.
The problems of using natural colours were presented in some detail by Giles Drewett (Overseal Natural Ingredients). Two types of natural colours are offered by Overseal: formulations using colouring pigments produced by nature, some of which may have been subsequently modified by a number of processes including saponification, lake formation or metal exchange, and foods that provide colour without being selectively extracted or isolated, such as fruits, vegetables, berries, spices and edible plants. Drewett warned of the dangers of instability when some of these are exposed to heat and light or extremes of pH but showed that a range of stable colours from natural sources was possible.
Another trends presentation came from Trevor Barker (Cornelius Group) who said that there are three main senses used in the evaluation of cosmetic and personal care products. Whilst visual and olfactory stimuli have long been fundamental in this process the feel of the product has not always been given such consideration. Cornelius has created a range of interesting textures that can be applied to a number of formulation types. The use of novel silicones, esters and gelling agents along with waxes and nonionic surfactants allowed for some experimental blending to create novel feeling bases that can be incorporated into end formulations. This portfolio of interesting textural formats can then be used as a basis for the development of innovative new product concepts across the whole cosmetics and personal care sector (see p36-38 for full coverage of these concepts).
SILICONES & SUN CARE
No ingredient conference is complete without updates on silicone technology and the latest advances in sun protection. Various speakers discussed the former including Sabine Nienstedt (Momentive Performance Materials) who described how silicones can add benefits to cosmetic formulations; Juergen Meyer (Evonik) who presented a new silicone-based high performance emulsifier and Tony O’Lenick (Siltech) who discussed the surface activity of silicones.
The application of cosmetics to hair and skin is always based upon the formation of new surface area, said O’Lenick. For efficient spreading there has to be a lowering of surface tension and O’Lenick showed how the addition of 0.5% by weight of various silicone products to various oils could significantly lower the surface tension of the latter. The structure and properties of the silicone compounds were compared and how these improved formulations was discussed. O’Lenick also introduced the word siliphilic - ie makes them feel more silicone-like - to describe their effect on oils!
Representing advances in UVB protection Jeroen Van den Bosch (Umicore Zinc Chemicals) spoke about inorganic UV absorbers for maximum broadband UV protection and Julian Hewitt (Croda Europe) presented flexible formulation systems for elegant daily UV protection products. Hewitt first showed how products based on micronised titanium dioxide have become more transparent as the technology has advanced over the last two decades and how it is now possible to prepare transparent and elegant formulations using Clarus CT-200 or Clarus CT-10W dispersions. To these may be added Optisol, a TiO2 material doped with manganese to act as a free radical scavenger. The beige colour imparted by this is reasonably close to that of human skin. To obtain higher SPFs it is usual to mix organic and inorganic absorbers but recent work at Croda has shown that adding just 2% SolPerForm 100 to a system based on Clarus CT-200 can double the expected result.
There is always a temptation to leave early on the last day to get ahead of the traffic but not before hearing Barbara Brockway (IMCD UK) explain how peptides are changing the face of skin care. The first amino acids, peptides and proteins were used in skin care as film formers, conditioners and moisturisers. Enzymes in cosmetics first found use as exfoliants and are now being used in bioconversions to synthesize specific peptides. Their activity depends on their shape; for example a distinctive feature of collagen is the regular arrangement of amino acids in each of the three chains of the collagen sub-units. The sequence often follows the pattern Gly-Pro-Y or Gly-X-Hyp, where X and Y may be any of various other amino acid residues. Gly-Pro-Hyp occurs frequently. Tripeptide-29 has this Gly-Pro-Hyp arrangement and stimulates collagen production and inhibits collagen breakdown by inhibiting MMPs that destroy the skin’s extracellular matrix. Brockway described various peptides and their properties in skin care in what was a totally fascinating presentation.
