Skin, hair & beyond
In addition to the show, in-cosmetics offers scientific and marketing conferences plus innovations seminars featuring supplier presentations about the latest cosmetic ingredients and product concepts. John Woodruff reviews the latter from Amsterdam 2008
In addition to the show, in-cosmetics offers scientific and marketing conferences plus innovations seminars featuring supplier presentations about the latest cosmetic ingredients and product concepts. John Woodruff reviews the latter from Amsterdam 2008
?There is no particular theme to the in-cosmetics innovations seminars, although many cover similar subjects. Hair care was well represented with offerings from BASF, Seppic, Lubrizol, Ciba and McIntyre.
BASF discussed Luviquat Sensation, an aqueous solution of a copolymer of vinyl pyrrolidone and vinyl imidazole and poly-diallyldimethylammonium chloride [INCI: Polyquaternium-87], designed to be added to shampoos at relatively low concentrations to impart conditioning properties. Despite Luviquat Sensation’s high cationic charge density, it can be formulated with a broad variety of anionic surfactants. According to Serge Rogasik of BASF, when hair is washed with a shampoo containing Luviquat Sensation an extremely thin structure is formed without causing build-up, making the hair feel soft and natural. The feel is said to be silicone-like with slip and the hair is easy to comb. Because the film is only 10-20nm thick it does not add weight to hair and depending on the usage concentration, hair volume can be controlled and frizz reduced.
Nathalie Chevrot discussed products produced by Seppic for hair in crisis. These included Sepicap MP, described as a multifunctional thermo-activated protection material for hair damaged by the sun, by dry blowing and by pollution or chemical treatment products. It is a combination of amino acids and panthenol [INCI: Sodium cocoyl amino acids/potassium dimethicone copolyol panthenyl phosphate], which protects the roots and prevents the formation of peroxides in the hair shaft.
The second material was Aquaxyl [INCI: Xylitylglucoside; anhydroxylitol and xylitol], a material better known for its skin moisturising properties, but the addition of 1.5% of it to a shampoo greatly increases the moisture content of hair. Lipacide C8G is capryloyl glycine and this was suggested as a dermo-protector for itchy scalps. Sepicalm VG is an extract of Nymphaea alba with sodium palmitoyl proline, suggested to soothe scalp irritation. Lipacide C8G and Sepicalm VG at a level of 2% were also said to improve oily hair and to mitigate dandruff.
Tony Watson described Tinovis CD from Ciba as a new cationic liquid dispersion polymer that provides focused conditioning for hair without unwanted build-up. It has excellent sensory properties for hair and skin care applications and enhances performance of hair and skin care actives, said Watson. The polymer has greater substantivity at the tip and middle of the hair shaft, where the most damage occurs, and lower substantivity at the root where there is little damage. It provides a soft, silky feel and leaves the hair healthy looking and easy to comb when wet or dry. In addition, Tinovis CD [INCI: Dimethylacrylamide/ethyltrimonium chloride methacrylate copolymer; propylene glycol; dicaprylate/dicaprate; PPG-1 trideceth-6 and C10-11 isoparaffin] works synergistically with conditioning agents and other actives, aiding in their even distribution and deposition to help improve the efficacy of hair and skin care formulations.
The Lubrizol/Noveon presentation given by Dorina Ghirardi described fixative polymers sold under the Fixate trade name. Fixate Superhold polymer is designed for stiff hold, humidity resistance, superior performance and styling versatility. Fixate Plus polymer [INCI: Polyacrylate-14] combines long lasting style support and exceptional humidity resistance and Fixate G-100 polymer [INCI: AMP-Acrylates/allyl methacrylate copolymer] is an acrylic copolymer and hair fixative having a highly branched structure with distinct hydrophilic and hydrophobic domains. A broad range of hold and stiffness levels can be achieved with various usage levels and formulation techniques. It provides clear, uniform films with good adhesion, enhanced humidity resistance and a smooth, natural feel on hair. The controlled hydrophobic association of this alkali-swellable associative polymer enables improved thickening efficiency, while maintaining smooth, clear, aesthetically pleasing gels with shear-thinning rheology, said Ghirardi.
SUNNY OUTLOOK
Sun protection products are usually an important part of cosmetic science events and this was certainly the case in Amsterdam with several presentations on the subject. Julian Hewitt of Croda Suncare posed the question: Natural sun protection; can we make an effective green sunscreen? He said that adding Aloe barbadensis juice or other botanical extracts to a sun protection product did not make it natural. Croda had recently published its Green Guide and stated in that products claiming to be natural should be derived from renewable vegetable sources, mineral sources or unharmed animal sources. They should not contain ethoxylates or propyloxylates nor phthalates, parabens, formaldehyde releasing preservatives or petroleum distillates and should not have been tested on animals in at least the last ten years for any purpose.
Hewitt then asked whether any sun filters could be termed natural. None of the so-called organic filters pass all the criteria and no natural materials are listed in the positive list of acceptable sunscreens. This only leaves microfine titanium dioxide and zinc oxide. Unfortunately as these are less than 100nm in diameter they are nano-sized particles, which are not allowed by the Soil Association in its certified products. However, the Environmental Working Group (EWG) states that TiO2 and ZnO are the safest and most effective sunscreens available. Hewitt then went on to describe various TiO2 and ZnO dispersions and gave illustrative formulations in which all ingredients met the Green Guide criteria.
Global harmonisation of permitted sunscreen materials, their levels of use and methods of testing is a long awaited dream of international suppliers of the actives and finished products. Uli Osterwalder of Ciba Speciality Chemicals described the background to sun protection and the need for UVA protection, which releases reactive oxygen species within skin that may lead to skin damage and cancers. He said that white skin has an SPF of 1 whereas black skin has a natural protection factor equivalent to SPF13. Tinosorb M and Tinosorb S are to be globally accepted and they provide the UVA protection level suggested by the Colipa Guidelines published in 2007, which in effect require sun protection products to have UVA protection equivalent to at least 3* on the Boots system. Osterwalder described various methods of measuring UVA protection and ways of expressing these.
Photostability of sunscreen actives was described by Christine Menok-Edinger of DSM Nutritional Products under the title Photostable UVA protection in sunscreens - practical solutions. Typical sun care products require SPFs of 30 and a high level of UVA protection, she said, and solar exposure may alter the chemical integrity of UV filters and in due course their physical properties. One of these filters is the UVA filter butyl methoxydibenzoylmethane (BMDBM), known as Avobenzone in the US. In the DSM comparison study various products suggested for stabilising BMDBM were tested by two different methods: photostability after irradiation and the new Colipa Method for the in vitro Determination of UVA Protection (2007). Results showed that octocrylene is the most effective stabiliser of BMDBM and that it is possible to achieve 90% photostability of BMDBM with excellent PFA factors after pre-irradiation. Various formulations of effective sunscreens with high and stable UVA protection were also described.
SKIN CONCERNs
It is now generally accepted that solar radiation is the principal cause of damage to the skin and there were various presentations given on ways of improving skin condition. Martin Albrecht of Kuhs described a multifunctional lamellar system for barrier improvement of allergy prone, dry and eczema affected skin. Albrecht said that lamellar vehicles mimic the structure and physicochemical properties of the lipid lamellar layers of the stratum corneum and in so doing can enhance the barrier function of the stratum corneum and achieve clinical improvements.
Many skin creams contain classical emulsifiers to combine the hydrophilic and lipophilic phases of the formulation, said Albrecht. However, depending on the emulsifier or the emulsifier mixture, the lipids within the stratum corneum may also become emulsified. A comparative study provided an objective assessment of how a conventional emulsifier and a lamellar system affected the layers of intact and damaged skin. Results show that a system provided by Kuhs and trade named DMS stabilises the lipid barrier of the stratum corneum. DMS stands for Dermal Membrane Structure, a system developed to mimic the skin itself, and a cream based on DMS is likely to reduce the potential for skin irritation and may be better accepted by those susceptible to such irritation.
Skin tone is altered by sunlight and uneven colouration is a major contributor to the visible signs of ageing. Heliostatine IS was described by ISP’s Joel Mantelin as a new material for homogenising skin tone. It is an extract of Pisum sativum (pea) in an aqueous/glycerin mix and is designed to promote a healthy glow and radiant complexion by increasing melanin synthesis in the skin. It is not a sunless tanning agent and is more effective if applied after UVB exposure. In-vivo tests illustrate the regulating effect of the compound on the melanin index over a period of 28 days, showing an increase after approximately three days that is maintained for as long as the product is applied. It was also claimed that Heliostatine IS enhances skin feel by inhibiting interleukin 1ß, a cytokine thought to play a key role in the inflammatory response.
Skin lightening was also of interest to many delegates and Lipotec’s Cristina Carreno described a new molecule for skin lightening, which acts by inhibiting tyrosinase activity. INCI named Dimethylmethoxy chroman palmitate, it exhibits a considerable lightening effect on the skin, has a completely safe profile, shows good stability in formulations and possesses a photoprotective effect on human epidermal keratinocytes, helping to prevent skin damage caused by UV radiation.
SENSORY CUES
Product rheology is one of the most important parameters of cosmetic products, contributing to product stability, suspension of particulates and consumer perception. Strategies in selection of rheology modifiers was the subject of the presentation by Anju Bansal of CP Kelco, which supplies a number of different materials with widely different properties. Axcel CG-PX is microfibrous cellulose with xanthan gum obtained by the fermentation of glucose syrup. It forms a
3-dimensional pseudoplastic network in water, which after high shear activation imparts suspending properties without adding to the perceived viscosity. Axcel CG is compatible with surfactants, is stable across a broad pH range and is salt tolerant. It is used at 0.05-0.2% in shower gels, liquid soaps and bath foams and can be used to suspend encapsulated actives or particulate matter for a scrubbing action or to achieve visual effects.
Bansal also described the well known Keltrol CG range of xanthan gums, which show pseudoplastic rheology and are used to impart stability to emulsions and improve suspension of pigments in make-up products. The Kelcogel CG gellan gums are also used as emulsion stabilisers and for suspension of pigments and particulates and may be used in spray applications such as sunscreen spray. Also described were Cekol cellulose gums that provide smooth, non-gelled viscosities with Newtonian flow and find frequent application in toothpastes and make-up. Carrageenan is from red seaweeds and is supplied under the Genuvisco trade name and finds particular application in the presence of electrolytes and surfactants to prevent product syneresis and provide clear gelling properties.
SensiMap is the name given to a particularly interesting concept of customising sensory effects in a presentation by Bryan Moran of Noveon Consumer Specialities. Described as new ways to think about oil-in-water emulsion skin care sensory properties, Moran said the initial texture elements were provided by Carbopol polymers and then cosmetic esters were added to enhance sensory effects from rub-out to after-feel. It enabled a combination of texture and traditional sensory elements to deliver the right skin feel at the right stage during application.
Moran produced a simple four-field matrix labelled luxurious, indulgent, refreshing and surprising. Both axis were labelled from light to heavy; the vertical axis was represented by various Carbopol grades while the horizontal axis included various esters. It was suggested that there are three stages of application: rub-out 1, characterised by wet skin feel from the aqueous external phase; rub-out 2; the wet feel subsides but fluid texture remains and the sensory contribution from the non-aqueous phase begins to dominate; and after-feel when the sensory properties are dominated by the non-aqueous internal phase of the emulsion. Choice of Carbomer affects the initial rub-out phases and choice of esters affects the final after-feel. Examples of using this technique were described and in his summary Moran said that the SensiMap concept may be used as a template to create formulation themes, which facilitate the creation of end consumer experiences that deliver against product promises and marketing claims.
No fewer than four presentations illustrated the wide fields of interest by ISP. In addition to that by Joel Mantelin on skin tone, Ben Sales discussed ISP Captivates as a way of creating value-added products, advanced moisturisation was presented by David Moore and Isabelle Imbert showed the role of mitochondria in anti-ageing products. ISP Captivates are microcapsules using complex coacervation suitable for encapsulating oils, butters and waxes together with other lipophilic ingredients. Their size varies from 5 - 2000 microns, their colour can be adjusted to match Pantones and the wall thickness varied to give the desired break strength.
ISP Captivates can be used to provide colour bursts in surfactant systems or to provide smooth colour rub-out in leave-on formulations so colour is released when required. Microcapsules can also be used to protect and stabilise sensitive active ingredients such as BMDBM, which is incompatible with formaldehyde donor preservatives and metal oxides. Capsules of 10 microns can provide even coverage on the skin without loss of UVA protection efficacy. Some water-soluble actives may also be encapsulated, including vitamin C.
A different type of particulate additive is Orgasol Caresse [INCI: Polyamide-5] from Arkema, described by Karin Loyen as a new copolymer of Polyamide-12 and Polyamide-6 with an average particle size of 10µm and a unique round micro-sponge structure. It has combined hydrophilic-lipophilic absorption properties, which make it suitable for dispersion in o/w emulsions, and it has a particularly high oil absorption capacity to impart a velvety feel to skin. It can be added to emulsions to improve texture and give a soft focus effect and can control sebum in greasy skins.
Presentations covering anti-ageing products appear in the June 2008 issue (p32-35).
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