Creative Developments (Cosmetics) Limited
Hair Care: SPC 2002
John Woodruff
Hair care in its many aspects was an important part of the 22nd IFSCC Congress in Edinburgh, 2002 and was the subject of six podium presentations and ten posters. The emphasis was on its properties and ways of measuring them; hair damage, its causes and possible means of prevention, and on its colour and various methods of changing it. It came as no surprise to hear that most hair damage is caused by cosmetic treatments but at least we can minimise the effects and cover up that which we cannot prevent. The other major cause is solar radiation but other than its effects on hair colour, surprisingly little was discussed in this area.
In contrast to skin, hair fibre does not possess its own biological protective and repairing mechanisms against the impact of environmental effects. This means that protection must be given by an appropriate hair care treatment. Described in a poster1 at the congress were laboratory models used to illustrate environmental damage and the limiting effects of certain ingredients. Tresses of virgin human hair previously cleaned by standard shampoo were subjected to repetitive cycles of car exhaust gas and UVB irradiation. After three cycles hair surface damage was quantified by dry combability measurements.
A second model used hair subjected to two washes from a bleaching shampoo, which renders it more porous, and then exposing the rinsed and dried tresses to 10mg of vegetal charcoal. The charcoal adhering to the surface can be quantified using SEM and image analysis and is a measure of hair porosity and surface roughness. Damage by solar radiation can be measured by recording the loss of the amino acid tryptophan, and also by a reduction in mechanical strength. The authors used the models described to evaluate the effects of an active ingredient based on proteins from Moringa Oleifera incorporated into a shampoo formulation and hair protection against city pollution imparted by an active ingredient based on flavonoids from Adansonia digitata when incorporated into a leave-on lotion, which also reduced UVB-induced hair damage.
Shine is
an important attribute of beauty associated with clean and healthy hair. Claims
for increased hair shine, gloss or lustre are frequent for hair cosmetic
consumer products, as well as for the materials they contain. Hair shine is
generated when a beam of light strikes the hair surface and fractions of light
that are reflected generate surface
highlights and brightness contrast that give the impression of shine. The
authors of a podium presentation2 at the IFSCC Congress measured the light reflected from single human
hairs over a wide range of angles by laser-based, multi-channel
gonio-photometry. The curves for angular light intensity were analysed by
fitting Gaussian distributions to determine specula and diffuse reflection,
respectively. It was concluded that shine of a hair collective is essentially
dependent on single fibre contrast. The authors proposed a “gloss index” as a
reproducible mathematical expression of shine. The method was used to study
hair of various types and to measure the improvement in hair shine when treated
with hair spray and with henna, both of which significantly increased the “gloss
index” value.
There has been a significant increase in the styling resins available for hair product formulation in recent years. Hair styling products are a compromise between hold and a natural appearance. Consumers want a soft flowing look but need the hair held in place throughout the day. New from National Starch Personal Care is an anionic polyurethane-14 AMP-acrylates copolymer trade named DynamX that creates a flexible yet very strong film on hair. The polymer is said to bond to hair better, offer superior film toughness, be faster drying and give more flexibility and a better feel than existing styling polymers, resulting in a strong hold and flexible, natural motion of the hair. Films formed with DynamX are transparent, flexible and can be stretched. The material is pre-neutralised and is soluble in aqueous-alcoholic solutions.
Clariant supply the Diaformer series of acrylic polymers that are designed for use in pump and low VOC applications. They are amphoteric products with either a carboxylic betaine or amine oxide structure, giving then excellent affinity for hair and enabling the formation of a uniform film. They result in flexible, natural styles or crisp and crunchy effects, depending on the Diaformer used.
Fixomer-A28 and Fixomer A-30 are styling polymers from Ondeo Nalco. They are copolymers of methacrylic acid with sodium acrylamidomethyl propane sulfonate and are said to give exceptional hold under conditions of high humidity. They are anionic and water-soluble and compatible with carbomers to give clear gels. The same company also supplies Sensomer CI-50, which is a cationic-modified potato starch used as a conditioning aid in shampoos and conditioning rinses and also in styling products. It is composed of approximately 75% amylopectin and 25% amylose, a synthetically modified monosaccharide, and has the INCI name, starch hydroxypropyltrimonium chloride. It may be used as a substitute for guar hydroxypropyltrimonium chloride and because it is already in aqueous solution it is easier to process and is claimed to provide much clearer products.
Continuing the natural theme, Oligoquat M is a naturally derived, quaternised oligosaccharide from Arch Personal Care that is ideal for use in rinse-off and leave-on skin and hair care applications. It is a modified sugarcane plant oligosaccharide with a cationic charge. This affords a product that retains the moisture-binding properties of simple sugars and is extremely substantive to the hair and skin, a property most commonly associated with high molecular weight polysaccharides. Oligoquat M, proposed INCI name dihydroxypropylstearyldimonium oligosaccharides, can help to smooth and repair damaged hair cuticles leaving a brilliant, healthy shine on the hair. Arch also supplies a mixture of plant-derived amino acids trade named Phytokeratin, that are adjusted to be in the same proportions as those in human hair and also alcohol-soluble and oil-soluble amino acid mixtures and a quaternised version for hair conditioning.
Another natural film former is Amaze from National Starch, which is a modified cornstarch that is non-tacky in use and provides good hold with excellent resistance to humidity. Jojoba Pro-HP is the trade name for hydrolysed jojoba proteins from the Desert Whale Company USA. In common with other hydrolysed vegetable proteins they form hydroscopic films on the hair shaft. The film is semi-permeable and a clear reflector of light that improves shine and enhances hair colour. This is one of a small family of ingredients based on jojoba proteins from the Desert Whale Company.
Protection is a much used term in hair
product marketing; protection from the environment; protection from chemicals
during permanent waving, bleaching and colouring; protection from solar
radiation; from split ends and hair damage caused by combing; from microbial
infection, from dryness, dullness and the effects of ageing and from every
other stress imaginable. A variety of ingredients are available that are
claimed to impart protection against at least some of these deleterious
effects.
A podium presentation3 at the IFSCC Congress described work to identify the cause of damage to hair during oxidation dying, which established that it was oxidation of hair lipids by the hydrogen peroxide, The authors then searched for natural plant extracts with a protective effect during oxidative hair dying and found that Rosmarinus officinalis (rosemary) extract, Origanum (marjoram) extract and Camellia sinensis (green tea) extract had a protective effect and they exhibited a synergistic action when used together. It was proposed that the antioxidant properties of the extracts reduced hair damage and did not interfere with the colouring process.
Solar radiation is the cause of many hair problems. The S-S bonds are disrupted within the hair fibre, causing a loss in cystine and a corresponding increase in cysteic acid. This has a major impact on the mechanical properties of the hair, resulting in a loss of tensile strength and an increase in porosity. UV damage at the hair surface reduces its tryptophan content and causes the cuticle to become roughened, affecting the texture of the hair and making it harder to comb. Also not only are hair colorants bleached by sunlight, melanin is also lost and the natural hair colour affected.
Although
commercial sunscreens can act to reduce this damage, they were designed for
application to skin. As such, they are intended to be applied from a leave-on
product, and with their oily nature, tend to weigh down the hair. Also
conventional sunscreens are not substantive so, when applied from rinse-off
products they are also rinsed off. To counter these problems several sunscreen
materials have been specifically developed for application in hair products.
Well established is Escalol HP-610, ISP, Europe, which is dimethylpabamidopropyl
laurdimonium tosylate with propylene glycol stearate. It is a cationic
material, which increases its substantivity to hair, and is best applied at
between 0.50% and 2.0% in a conditioner-type formulation.
Croda Oleochemicals, UK, offers Polquaternium-59 in butylene glycol
as Crodasorb UV-HPP that is claimed to protect the hair against photo-damage.
It is water-soluble and may be delivered from a shampoo system and studies show
significant protection against solar radiation, which results in less colour
loss, an improvement in hair strength and easier combing than hair that has not
been treated. Helioxine (Silab, France), is an active ingredient
obtained from Helianthus annus (sunflowers) that is described as rich in
photoreceptors and polyphenols, which protects the hair and skin from the
harmful effects of photo-induced free radicals. It is said to reduce the
peroxidation of intercellular lipids inside the hair and prevent disruption of
the cuticle.
Many film-forming materials adhere to hair
and protect it from moisture loss and improve combability. Protein materials
are often suitable in this context but most have too large a molecular size to
penetrate the hair. Setakol, Pentapharm, Switzerland, is a hydrolysed
silk protein that the suppliers claim penetrates the hair to form an adhesive
protective film that cements and seals the hair cuticle from within. The hair
becomes smooth and easier to comb and its sheen and elasticity is improved.
Hydrosolanum, Croda Oleochemicals, is
a hydrolysed vegetable protein with a low molecular weight (600) that
penetrates the cuticle of hair to reach the inner cortex. The vegetable
peptides plasticise the hair fibres, which can lead to a reduction in split
ends. It also has moisture retention properties and studies show that it
improves combing properties and hair fibre structure. Also from Croda is
Keravis, which is said to penetrate hair to improve its strength in three
measurable ways; its tensile strength, its bending modulus and its resistance
to flexibrasion. The material is a complex of hydrolysed vegetable protein with
PG-propyl silantriol that is water-soluble and can be added to a variety of
hair products to protect it during chemical processing.
Many other protein-based materials for hair
care are available from Croda and from other suppliers including the Aqua Pro
series from Midwest Grain Products, Chemyproteins from Chemy-Union, the
Gluadin series from Cognis, Glusols from Kelisema, the Hydrocolls
from Arch Personal Care and Naturein peptides from Quest
International. Other suppliers include Coletica, McIntyre and
Maybrook and Seiwa Kasei offers an extensive series under the
Promois trade name. Proteins are used as the surfactants in shampoos and
conditioning products; Sinerga provides a number based on soy and wheat
proteins, and materials from Tri-K Industries and EOC Surfactants NV include
proteins as the hydrolysate, in anionic form for shampoos and as quaternary
salts for conditioning. There are numerous other examples and readers are advised
to look at the Raw materials Directory, SPC August 2002 for further details,
and for the addresses of the suppliers mentioned in this feature.
Described as a natural restructuring agent
for hair, Amanduline SG, (Silab, France), is a hydrolysed sweet almond
protein from Prunus dulcis that, because of the high affinity of the
keratin peptides of hair and the almond peptides of Amandulaine, it has a high
substantivity for hair. Areas of damage on the hair shaft result in an
increased negative charge, which increases the substantivity of the cationic
Amanduline to these areas. Because the material consists of branch-chained
glucosides and peptides the film formed on the hair improves its structural
integrity and is said to add volume and shine to the hair fibres. Dimethicone
copolyol meadowfoamate, Fanning Corporation, USA, is also substantive to
hair with claimed restoration and strengthening effects and the same company
supplies many other materials of interest for hair product formulation.
Improving hair strength is a much sought after attribute for hair products and the focus of frequent claims and was the subject of a podium presentation at the IFSCC Congress. The authors described the development of a polymer4 that coated individual hair fibres to act as an artificial cuticle. Betafin, Finnfeeds, Finland, is a natural betaine with a trimethylglycine structure that is extracted from sugar beet molasses by a chromatographic separation technique. Work by Hazel Poole Associates showed that treating chemically damaged hair with this material significantly improved its strength5.
A growth
area in application but one that appears to have been overlooked by the
majority of ingredient suppliers is that of fudges, muds and moulding clays.
These products are a reversal of the trend towards lighter, clearer less tacky
products but are a necessary part of today’s hair styling repertoire. Whereas
the majority of styling products do not want tack these products are often
liked because of their sticky stringiness. Most are loaded with petrolatum and
lanolin and contain paraffin wax or ozokerite to give stiffness and a styling
resin to improve set. Zenitech, USA, has some interesting materials that
can be recommended for these applications. They are based on castor oil and/or
beeswax and can be added to give shine and body to the hair. Cosmetic
Rheologies, UK, has produced some starting formulations based on its
Rheocare range of rheology modifiers.
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