in-cosmetics seminars - all in the mix

John Woodruff reviews a personal selection from this year's innovation seminar programme at in-cosmetics

John Woodruff reviews a personal selection from this year's innovation seminar programme at in-cosmetics

RHEOLOGY MODIFICATION

The first of several talks on rheology modifiers came from Dorina Ghirardi (Lubrizol Advanced Materials) under the title Creating the right sensory with the right choice of Carbopol polymers. Ghirardi said that understanding the product’s basic structure is a critical factor in predicting the sensory attributes of the finished product. However, typically most cosmetic sensory studies are linked to emollients or to other components bearing sensorial modification properties.

Acrylate polymer-based rheology modifiers form microgel networks, modify rheology and stabilise emulsions through a space-filling mechanism. They occupy the entire aqueous phase of the formulation and control the release of the aqueous phase and the dispersed phase. Ghirardi focused on the different properties of commonly used short to medium flow acrylate polymers and how they can affect the sensory attributes of the end products. Ghirardi also explored the aesthetic contributions of the different polymers in the different phases of sensory evaluation.

The presentation aimed to aid formulators in achieving the desired formulation’s sensory properties from the very first time with the right choice of acrylate polymer-based rheology modifiers. Their tolerance to electrolytes, their flow behaviour at low and high rates of shear and their sensory footprints were all described. In summary Carbopol Ultrez 10 and Ultrez 21 polymers provide refreshing sensory in initial rubout and are good for refreshing formulations while Ultrez 20 polymer offers luxurious feel and longer playtime and is good for rich cushiony and non-watery sensory gel formulations.

A rheology modifier for elegant skin feeling and active enriched skin care formulations was described by Volker Wendel (BASF). BASF has developed a new rheology modifier designed to fulfil the formulator’s requirements for both elegant skin feel and salt stability. Luvigel STAR was described as a non-ionic associative rheology modifier developed specifically for skin and sun care applications. Because of its innovative polyurethane technology Luvigel STAR was said to provide outstanding thickening efficiency, even under challenging conditions such as high salt concentrations or extreme pH values where most rheology modifiers normally fail to perform. In addition to being suitable for producing a wide range of formulations, from light lotions to thick creams, Luvigel STAR also provides products with a luxurious skin feel, said Wendel.

The role of polymers in providing new appearances and trends in toiletries was presented by Giuliana Picciocchi (3V Sigma). By utilising the unique characteristics of Synthalen W2000, Synthalen W400 and Stabylen 30 it is possible to formulate products containing silicones, oils, opacifiers, capsules and suspended air bubbles.

Under the somewhat whimsical title of Multifunctional thickening and stabilising liquid polymer to wrap yourself with tenderness Alicia Roso (Seppic) described the properties of Sepiplus S. This multivalent polymer combines thickening and texturing properties with emulsifying and emulsion stabilising effects. It is an efficient thickener in the presence of high electrolyte levels and over a wide pH range. It is also pre-neutralised and in liquid form, rendering it flexible and easy to use, and is suitable for cold processing.

Polyquaternium-86 is a cationic thickener, described by Peter Hössel (BASF) as a styling and conditioning polymer for hair styling gels with improved overall performance. In comparison to styling gels with conventional anionic thickeners, Polyquaternium-86 allows advanced styling and setting in combination with PVP and VP-copolymers, even at high humidity. The cationic nature of Polyquaternium-86 together with its tailor-made shear-thinning rheology provides properties like creamy texture and the ability to re-style the hair plus excellent combing behaviour without sacrificing gel clarity

ENHANCED PROTECTION

As with many of the materials presented this year, Ultrathix P-100 is not a new material but a better understanding of its properties leading to new applications make it a material of interest. Ultrathix P-100 [INCI: Acrylic acid/VP crosspolymer] is an established rheology modifier suitable for use in a variety of personal care product types ranging from creams and lotions to hair styling products.

Tony Gough (ISP Europe) described new work that demonstrated an additional utility of Ultrathix P-100 in the formulation of sun care products. In addition to giving an elegant feel when used as a thickener and co-emulsifier in sun care creams and lotions, it was found to be compatible with the inorganic sunscreens titanium dioxide and zinc oxide. It also has relatively good tolerance to electrolytes and can improve the water resistance of sunscreen emulsions by up three times compared to similar compositions without Ultrathix P-100. The improved emulsion stability of sunscreen products containing Ultrathix P100 was dramatically illustrated by photomicrographs.

Sun protection products were a major theme in the seminars and Olga Dueva-Koganov (Ciba/BASF) discussed the importance of polymers in the development of effective water-resistant sunscreens. Luigi Rigano (Kalichem) talked delegates through his research for a cosmetic use for hydroxyappertite and his discovery that it improves the SPF of sunscreen products while Sabine Hitzel (Merck) described how assembling a chronoactive with water dispersible UVA capsules resulted in superior sunscreen products. The UVA filter is encapsulated in silica, which maintains its UV absorbance whilst protecting it from degradation. Hitzel claimed that this extremely safe UV filter technology shields the skin surface from UV radiation while the intelligent antioxidant forms the dynamic second defence line against damage to skin.

Uli Osterwalder (Ciba/BASF) described the requirements for daily UV protection. UV radiation is a function of season, latitude and time of the day and exposure patterns of people differ during work and leisure time. Osterwalder described the different protection profiles of existing sunscreens and day creams and proposed an ideal protection profile and strategy to avoid premature skin ageing and skin damage.

Julian Hewitt (Croda) is a regular speaker at scientific conferences and at in-cosmetics he presented new developments in UV protection, outlining a strategy for achieving high SPF in sunscreen formulations by making use of aqueous inorganic sunscreen dispersions with oil-soluble organic UV filters. This approach allows for optimum distribution of the active ingredients in the formulation and on the skin and minimises any potential negative interactions. Hewitt pointed out the importance of selecting appropriate emollients to solubilise the organic filters and gave examples of suitable solvents. To be effective a sunscreen must form an unbroken film on the skin surface and this may be achieved by including Croda’s SolPerForm 100 in the formulation. This is a novel polymer that boosts the efficacy of sunscreen formulations by optimising the film forming properties on skin and does so without any negative impact on skin feel.

HAIR HIGHLIGHTS

Ingredients for hair products were well represented with presentations on hair conditioning and mild surfactants as well as ideas for improved styling. Silicones are synonymous with hair conditioning and several speakers introduced their company’s latest offerings. Sascha Herrwerth (Evonik) discussed Cutting-edge silicone-based conditioning technology with superior hair fibre protection properties.

Silicone derivatives are widely used in the cosmetics industry as they provide specific sensory benefits such as excellent conditioning properties in hair care applications or a smooth and silky skin feel in skin care applications. Silicone Quaternium-22 was said to represent a major step forward in silicone quaternary conditioning technology. Due to the unique triple cationic charge and T-shaped silicone backbone it possesses excellent substantivity to hair. Herrwerth said it offered impressive heat protection properties, improved colour wash fastness for dyed hair, superior skin feel and improved foam properties. Silicone Quaternium-22 is suitable for clear formulations and it can be incorporated into shampoo and conditioner compositions.

Ensuring good deposition of silicone additives on the hair is an essential part of good formulation. This aspect was the subject of the presentation by Bill Klein (Akzo Nobel) who described a study of the interaction of polymers with hair conditioner actives such as dimethicone, quaternium-18 and stearamidopropyl dimethylamine and dipalmitoylethyl dimonium chloride.

Several polymeric systems were evaluated in a typical hair conditioning formulation using wet comb panel tests. The influence of the polymers on the absorption of conditioner actives in bleached European brown hair was confirmed by surface specific x-ray photoelectron spectroscopy (XPS) analysis of the hair fibres.

As the conditioner actives adsorbed onto the hair fibre the hair specific disulfide and protein nitrogen signals were attenuated. The extent of attenuation allows the estimation of the adsorbed layer thickness. The spatial and depth distribution of dimethicone and nitrogen-based actives can be determined by monitoring the silicone and quaternary nitrogen signals. The study found that certain polymer materials enhance the adsorption of hair conditioner actives, which agreed with a higher preference in wet comb evaluations.

Silicones are not the only materials that improve hair condition and some companies claim a marketing advantage by avoiding their use. To meet such requirements Rhodia has developed Miracare SLB, described by Sandra Catarino as novel surfactant blends that form a liquid crystal surfactant phase in formulations. This liquid crystal phase consists of a close packed network of spherulites. These are concentric rings of lamellar surfactant bilayers, sometimes described as multilamellar vesicles, and are about 1-10 microns in diameter. Due to their form and elastic properties, spherulites can easily glide and slip within this network, providing the ability to formulate pourable liquids that can suspend insoluble oils and solids.

Other presentations from Rhodia were a guide through the green jungle by Barrie Shelmerdine (McIntyre) and a description of the properties of Jaguar C500 by Florence Bussod. Jaguar C500 claims excellent actives deposition, wet conditioning and foam enhancement using guar technology and is recommended for high performance shampoos and leave-on conditioners. It is said to provide weightless volume to give fine hair unmatched body and silkiness.

However silicones are so versatile that it is not possible to avoid them for long and Jurgen Meyer (Evonik) introduced a novel silicone o/w emulsifier, claimed to provide excellent stability, flexibility and sensorial properties. Various silicone-derived o/w emulsifiers were used in two very challenging formulations to compare stability at room temperature and at 40°C. The new material, Abil Care XL80, proved to confer much improved stability on both systems. Sensorial studies of typical emulsions using XL80 as the emulsifer gave positive results and various applications were described. In summary Meyer said that XL80 was suitable for formulations with pH 4-8 and for all types of cosmetic formulations. It is compatible with nonionic, anionic and cationic ingredients and suitable for all types of cosmetic oils and also showed good compatibility with UV filters and active ingredients.

ACTIVE EXTENSIONS

There were many other presentations including various ones on new actives to combat the visible signs of ageing and the introduction of various decorative make-up materials. Debra Jones (Croda) introduced Revitalix and Revitalix Nutra, both of which are based on a natural source of omega-3, -6 and -9 oils. Rivatalix is for topical application while the Nutra version is to be taken internally and is said to work with the body’s metabolic pathways to enhance the natural regenerative properties of skin.

Isabelle Imbert described how a new peptide developed by ISP targeted aconitase and cytochrome c-oxidase for a new mitochondrial anti-age strategy. And Oliver Paquette (Laserson) presented technological approaches developed by Japanese company Ichimaru Pharcos to address the requirements of anti-ageing, moisturising, whitening and anti-inflammatory cosmetics using plant extracts from exotic sources such as litchi and Japanese cherry tree.

Finally Christelle Graizeau (Jan Dekker) presented a fascinating study of extremophiles. These belong to the oldest life forms which colonise the earth under inhospitable conditions. To make cells stress resistant, extremophiles produce extremolytes or stress protection molecules. Originally discovered in salt-resistant cyanobacteria, Jan Dekker is now able to offer Glycoin Extremium, a highly concentrated and extremely pure form of an extremolyte. According to Graizeau, the new material increases the stress resistance of the skin cells by stimulating their self-defence system and not only increases cell viability in general but also protects and repairs the epidermis from UVA stress.

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