Creative Developments (Cosmetics) Limited
Skin
Care 2001
At
one time skin care cosmetics were applied almost exclusively to the face, neck
and hands. Now almost every area of the body has products specifically designed
for its care. This is good news for sales volume but gives the formulating chemist
ever more problems as marketing departments call for creative ideas for niche
products. For this feature I am going to offer a product idea for each of these
body parts, starting with the feet.
Cooling
foot sprays and lotions, with and without anti-fungal and deodorant additives
and foot scrubs with exfoliating particles have gained much in popularity.
Cooling effects can be obtained by using rapidly evaporating solvents like
ethanol but volatile cyclomethicones also leave a nice skin feel. Menthol and
peppermint oil confer cooling but for a longer-lasting effect Questice Plus, Quest
International, is described as a synergistic mixture of menthyl PCA and
menthol in dipropylene glycol and because it releases PCa by hydrolysis, it
also has moisturising properties. Another cooling agent is Frescolat from Haarman
& Reimer, which is menthyl lactate and virtually odourless. A suitable
vehicle for these materials is the Sub Micron Emulsion Concentrate" (SMEC)
from Arch Personal Care (formerly Brooks Industries), which is readily
diluted with water to form a lotion suitable for spray applications. It has low
emulsifier levels and is alcohol-free. The lotion is non-tacky and leaves a
smooth skin feel and the small droplets provide a rapid evaporation for a good
cooling effect and fragrance lift
Actiphytes
are a group of botanical extracts available from Active Organics.
Actiphyte of Soap Bark, Quillaja saponaria, forms a soapy lather when
mixed with water and is claimed to relieve itchy feet and athletes foot. Melaleuca
alternifolia (tea tree) oil is frequently used in foot products for it’s
anti-fungal properties but levels are often added below that required for
optimum efficacy because of its strong distinctive odour. From Honeywill
& Stein is lemon-scented Leptospermum petersonii oil, which is
claimed to have similar benefits to tea tree with a much more pleasant
fragrance. Southern Cross Botanicals of Australia offers tea tree oil
complexed with cyclodextrin as an odourless powder with slow-release
properties. The same company also produces pharmaceutical and water-soluble
grades of tea tree, a steam-distilled deodorised version and fine leaf powder
with 3% encapsulated tea tree oil for gentle exfoliation that could be useful
in leg-treatment products.
Removing
hard, dead skin from the heels requires gentle abrasion and whilst every
natural shell, seed and grain that can be ground to a powder is available for
exfoliation incorporating them into a product is often more difficult than
first appears. The particulates have a tendency to float to the surface or sink
to the bottom of surfactant-based products and in the low-viscosity lotions
that are suitable for foot products. It is a problem of product rheology rather
than viscosity and the answer lies in the yield value of the composition. Two
papers on the subject by Elizabeth Connock1,2 are available at www.connock.co.uk that explain how yield
value is determined and compare the results to those obtained by centrifuging a
wide range of materials in different bases.
Legs
may need depilation and moisturising. Knees may suffer from dry, rough patches
and thighs from cellulite. Other than depilatories the basis for these
products, like so many others in skin care, is a good moisturiser that is easy
to apply and has good penetrating properties. Triethanolamine stearate is a
satisfactory emulsifier system for cleansing products but has no place in
modern moisturising bases. Arlatone 2121, Uniqema, is a blend of sucrose
cocoate with sorbitan stearate that may be used at comparatively low levels for
the preparation of light, readily absorbed o/w emulsions. Two new emulsifiers
from Goldschmidt AG were introduced at In-Cosmetics 2001: Abil Care 85
is dimethicone copolyol dispersed in caprylic/capric triglyceride; it has an
HLB of 10 and forms light o/w emulsions that have a velvety-silky skin feel and
skin smoothing effect. Tegocare CG90 is cetearyl glucoside, a vegetable-based
emulsifier that is used at 1 –1.5% for the preparation of low viscosity o/w
lotions.
These
sugar-based emulsifiers, may be used to prepare light, cooling emulsions to
which anti-inflammatory additives can be added to soothe the legs after waxing
or sun bathing. Bisabolol from Matricaria recutita (chamomile), Arnica
montana and Glycyrrhiza glabra (liquorice) extracts have long been
favourite additives for their anti-inflammatory and soothing properties.
Canadian willow herb from Dragoco is said to be as effective as hydrocortisone
in reducing sting and inflammatory responses. Boswellia serrata
(frankincense) is used in Ayurvedic medicine for its calming, soothing and
anti-irritant properties and is available from Quest in isostearyl
alcohol as Soothex.
Many
other materials of natural origin are also of interest: for the relief of
“heavy legs” Sedema offers three products; Esculoside, an aqueous
extract of Aesculus hippocastanum (horse chestnut) said to be a venous
tonic with anti-inflammatory and free radical scavenging properties. Phytotal
VT, which has similar properties and contains aqueous and oil-soluble actives
obtained by hydro-distillation from Aesculus hippocastanum, Tilia
cordata (linden) and Cupressus sempervirens (cypress). Both products
are also recommended for anti-cellulite treatment compositions as they increase
cutaneous microcirculation. The third product from Sedema with claims to
improve blood circulation in the legs and thighs is Phytotonine, an
aqueous-glycolic extract of Arnica montana, Cupressus sempervirens
and Polygonatum officinale (Solomon’s seal). It is said to also be
suitable for treating rosacea, which is caused by deficient blood circulation
at the skin’s surface Literature to support claim substantiation is available
from the company.
Cellulite
is a problem caused by poor circulation and the build-up of fatty pockets of
adipose tissue. Cosmetic treatment by beauty therapists involves massage and
lymphatic drainage techniques and the use of products that help dissipate the
fat deposits and improve blood flow in the sub-cutaneous region. Croda
Oleochemicals offers Keratoline, a protease that is used to exfoliate the
skin prior to treatment with the lipolytic agents Coaxel and Plearimincyl in
anti-cellulite products. Croda also recommends Redulite, with diuretic
properties, and Phytotonine; a mixture of plant extracts to improve
microcirculation. Rhodysterol from Secma is a red seaweed extract with a
lipolytic effect on adipose cells. The efficacy of Rhodysterone has been tested
by both in-vivo and in-vitro methods and the suppliers claim an improvement in
appearance, texture and suppleness of skin when applied to the thigh area of
human volunteers. Alban Muller offers Slimming Phytomine Biocomplex,
which includes caffeine from coffee, theophyllin from tea, asiaticosides from Centella asiatica, and an extract of Aesculus hippocastanum. Exsymol
has a number of materials based on organo-silicone compounds such as
methylsilanol mannuronate (Algisium C) and a mixture of this with caffeine
(Cafeisilane C) is offered for slimming and anticellulite products. Exsymol
also supply a theophyllin derivative, methylsilanol carboxymethyl theophylline
alginate as Theophyllisilane C and publish extensive literature describing the
mechanism of cellulite and cellulite reduction with test protocols and results.
Moving
rapidly above the waist, stretch marks, stria disensia, can be reduced;
breasts may need firming and the area between and above them may be suffering
from too much exposure to the sun. This can extend to the shoulders and neck
where a good quality moisturiser with UV protection when appropriate, should be
used. Stretch marks may respond to gentle massage with an oil-rich emulsion.
For w/o emulsions with polar and non-polar oils, PEG-30 dipolyhydroxystearate
supplied as Arlacel P135, Uniqema, provides soft, glossy creams that are
very stable. Vitamin E, retinol and avocado oils have been recommended for
softening the stretch mark area and a follow-up with similar products to those
offered for breast-firming would seem to be appropriate. US patent 593,629
claims that stretch marks can be ameliorated or cured through the repeated
application of a topical composition containing between 5% and 15%
unsaponifiable lipids extracted from avocado seeds and that the effectiveness
of the composition is augmented by the addition of zinc and copper chelates.
Lady’s
mantle (Alchemilla vulgaris) is the plant of folklore for firming the
breasts. Bio-Bustyl, Sederma, is described as a biotechnological
filtrate containing growth factors that are claimed to stimulate collagen
synthesis and to restructure elastin, restoring firmness and elasticity.
Aosaine from Secma protects the skin from attack by elastase enzymes and
boosts collagen synthesis and cellular regeneration. Astrin-AG, Bioland,
is penta-m-digalloyl-b-glucose with anti-inflammatory and skin tightening
properties. Fermiskin from Silab is rich in oligosaccharidesa and uronic
acids from the Shii Take mushroom. It inhibits fibroblast synthesis of
metalloproteinases and improves the biomechanical properties of the skin.
A
natural indicator of the owners age are the brown spots commonly known as liver
spots or age spots that appear on the backs of hands. They are a
hypo-pigmentation response to exposure to UV light and are most extensive on
hands that through outdoor work, sports or sun worship have been exposed to
excessive solar radiation. Prevention through the use of sun protection
products is easier than finding a cure. Various materials can improve the
condition but the spots will soon reappear if the skin is exposed to sunlight
without protection. AHAs, retinol and retinal can be used to improve the
general look of the hands. Both retinol and retinal are important in the
physiological functions of vision, growth, reproduction and differentiation.
Retinol and retinal increase the thickness of the epidermis and improve
elasticity. Retinal is the aldehyde and retinol the alcohol form of vitamin A,
the retinoic acid cannot be used in cosmetic products in Europe.
Retinol
is present in fish liver oils as the ester retinyl palmitate and is available
as the palmitate from Roche and BASF and Dragoco, Libiol,
Collaborative Laboratories, Arch Personal Care, Rovi and Sederma
each supply it in combinations with other active materials claimed to
improve its efficacy and stability. Liposome preparations are popular carriers
for it and Gabriele Blume claims3 that by using this
carrier system the retinol will be transported into the deeper skin layers,
where it is able to develop the desired physiological activity at the target
sites. US Patent 5,492, 935 describes a composition containing retinal,
hydroquinone and glycolic acid and in clinical trials at the end of one month,
an improvement of age spots was clinically discernible. After two to three
months of topical treatment substantial improvement of age spots and fine
wrinkles occurred in 19 out of 23 subjects tested. Complete eradication of age
spots and fine wrinkles required two to six months of topical administration
but deeper wrinkles took longer to show any substantial improvement.
Aloesin,
Univera Pharmaceuticals, is a skin-whitening compound isolated from Aloe
plants. Chemically it is 2-acetonyl-8-glucopyranosyl-7-hydroxy-5-methylchromone,
which inhibits tyrosinase activity and it also lightens the colour of existing
melanin4. Vitamin C is ascorbic acid and this is an effective and
safe bleaching agent for kerato-pigmentation, but the material is unstable in
aqueous solution. Many ingredient suppliers have proposed forms that offer
improved stability and activity. Roche suggests Stay-C 50 and BASF
offers sodium ascorbyl phosphate. Tri-K propose Stableact-C, a
polyol-in-silicone system that encapsulates 12% ascorbic acid in an emulsion
that is then used to prepare a three-phase system in which the vitamin C is in
the polyol surrounded by silicone within the external aqueous phase. Chemdal
Corporation entrap ascorbic acid within micro-porous polymers to protect
its activity and the material is released over time when compositions
containing it are topically applied.
Arms
need moisturising with special attention to elbows. For treating dry, rough
patches on knees & elbows the dead flaky skin can be loosened by the
application of an AHA composition. There are many possible sources and either
the pure acid such as glycolic or lactic acid can be used or a natural
alternative such as Pronalen Fruit Acids from ProVital, which is a
mixture of Ananas sativus (pineapple) extract with Vitis Vinifera
(grape) and Passiflora quadrangularis (passionflower) extracts. Another
suggestion is Multifruit BSC from Arch Personal Care, which is a
combination of Acer accharinum, Citrus limonum Saccharum
officinarum (black strap) and Vaccinium myrtillus (bilberry)
extracts. The skin may then be smoothed and moisturised. Pseudocollagen from
Arch Personal Care provides a moisturising film and a smooth, non-tacky skin
feel. It is a high molecular weight yeast extract with properties very
similar to soluble collagen and is a suitable alternative for those not wishing
to use animal ingredients.
The
face is the reflection in the mirror in the morning and the part by which we
are recognised. However it represents only a portion of the total skin area,
perhaps this article will stimulate some ideas for the rest of the body.
1.
Physical Exfoliants, Connock E., www.connnock.co.uk
2.
Particularly Pretty Particulates, Connock E., www.connnock.co.uk
3.
Blume, G., Formulations Containing Retinol, Cosmetic Science
Conference, In-Cosmetics, Dusseldorf, 2001
4.
Jones, K., Aloesin, A Potent Skin Whitener, ibid