Transcript shampoo-2009

Shampoos
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The primary function of shampoo is to clean hair
and scalp.
 THE TERM:
The word comes from the Hindi “to press”.
Originally used in English for “massaging”
It still describes part of process of a Turkish bath.
 The first shampoos contained soaps (Sodium,
potassium
and ammonium salts of oleic and
coconut fatty acids), but these days they are based
on non-soap detergent (synthetic detergents have
replaced soaps as the primary surfactant in
shampoos because of their superior performance in
hard water).
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
The first large-scale development of non-soap
detergent took place in Germany during the
First World War (because fats were in short
supply)

The technology of complex shampoo emulsion
has also become more important as a result
of the development of effective two in one
shampoo, which clean and condition hair at
the same time.
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A WELL FORMULATED SHAMPOO
1. Should easily spread over the hair.
2. Produce a rich, creamy lather and stable
foam which easily rinsed out with water.
3. After drying, the hair should be left in
lustrous condition and easily manageable.
4. Surfactant level must be relatively high 10-
20%.
5. Viscosity at least 2000 cps
6. Must exhibit low skin and eye irritation.
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First shampoos (soaps) have several disadvantages
1. If they used with hard water or low pH,
they leave the hair with dull, tacky coating.
2. Soap solutions are alkaline, causing
roughening of scales of the cuticle, giving
rise to dullness and fly effect.
(Amine soap gives neutral solutions).
‫ ٭‬Nowadays, most shampoos are based on
synthetic detergent.
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TYPES OF SURFACTANT (DETERGENTS)
Anionic
Cationic
Non-ionic
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Anionic
The alkyl and alkyl ether sulfate represent two most
widely used classes of surfactant for the formulation of
shampoos.
1. Alkyl sulphates
C12H25O.SO3 Na+ → SLS
C12H25O.SO3HN(CH2CH2OH)3
→ TLS
They are usually mixture,C12 lauryl, C14 myristyl,
C16 cetyl, C18 stearyl.
Coconut oil contains 50% each of C12 and C14.
Lauryl produces the most lather and myristyl the richest
lather.
‫٭‬alkyl sulphate clean the hair well, and leave it shiny, but
they tend to strip the hair, leaving it unmanageable.
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2. Ether sulphates
C12H25 (OCH2CH2)n O.SO3Na +
Foaming potential decreases with the increase of
the number of (OCH2CH2) group, while mildness
and solubility increases. The optimum is 2-3.
They are generally more soluble than alkyl
sulphates.
3. Miscellaneous anionic surfactant
They are not widely used but incorporated with
primary ones as secondary surfactants, or used in
specialty product.
E.g. sulfosuccinates , linear alkylbenzene sulfonate .
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Cationic
Cationic surfactant in shampoo formulations is
more limited than that of surfactant classes.
They are not as effective detergents due to their
ability to strongly bind to hair’s negatively charge
surface, and not efficiently removed during rinsing.

Cetrimide is an example
CH3
|
C16H33 ― N+ ― CH3 Br–
|
CH3
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Notes
Shampoos containing only one of the previous
types of detergents tends to be harsh, and it’s
therefore necessary to add an auxiliary
detergent, usually weak detergents which:
1.
2.
3.
4.
Increase the viscosity of the shampoo.
Stabilize the foam.
Have conditioning effect on the hair.
Increase the solubility of the primary detergent.
Non-ionic
For example, polyoxyehtylene lauryl ether
C12H25 (OCH2CH2)23
 THE MAIN THREE TYPES OF NON-IONIC
DETERGENTS:
1. Fatty alkanolamaides ( The ethanol amides)
They work as foam and viscosity enhancers. The main
component is the uncharged nonionic amide.
The major concern in formulating with alkanolamides is the
potential for free amine, particularly diethanolamine (DEA), to
form carcinogenic n-nitrosamines.
E.g. lauric diethanolamide
O
║
CH2CH2OH
C11H23C-N
CH2CH2OH
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2. Amine oxide
Are prepared by the oxidation of tertiary amines with
hydrogen peroxide. They are best known for their ability
to enhance foam characteristic, and provide thick,
creamy, more stable lather at moderately acidic pH.
CH3
|
CH3 (CH2)11 ― N → O
|
CH3
e.g. Lauryldimethylamine oxide
 Nonionic surfactant are generally not used as primary
surfactants in shampoos due to inferior foaming
characteristics, which result from their large surface area per
molecule and the lack of charge on the surface films in
nonionic foams.
The advantage of the use of nonionic is their ability to reduce
eye irritation and sting.
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Ampholytes (Amphotrics)
- They have very low irritation potential and are almost completely nonstinging to the eyes.
- Can be formulated in many types of shampoos.
- Should avoid low pH when formulating because the amphotric become
positively charged since this can result in increased irritation.
CH3
|
_
C12H25 ― N + ― CH 2COO
|
CH3
N- lauryl betaine
Other Additives
Many additives associated with shampoos are added to
provide various additional benefits to the product;
some are critical and others are optional.
1. Viscosity modifiers
- Auxiliary detergents and conditioning polymers can provide a
thickening effect to a shampoo.
- Salts increase viscosity of detergent solutions, NaCl 1-2%,
Ammonium chloride at pH well below 7 to avoid liberation of
ammonia,
salting out mechanism (bell-shaped curve).
- Cellulose derivatives (0.5-1.5%)
2. Weak organic acids
A shampoo having the same pH as hair would do the least
damage.
‫ ٭‬Hair pH = 5-6
,
S. Detergent pH = 6-8
An addition of citric acid will decrease pH to optimum pH 5.5
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3. Opacifiers
The opacifying agent are usually stearates (stearic acid,
magnesium stearate, ethylene glycol monostearate), are used
in less than 1% concentration to give creamy appearance.
4. Antioxidants/ Sequestrants / UV Absorber
 Antioxidants are included in shampoo formulation to avoid
oxidation of unsaturated components, such as vegetable oil.
 Sequestering agent is included in shampoo to prevent
discoloration and to improve the performance of the anti
microbial agents by forming soluble complex with metal ions.
 Shampoo in clear packaging should contain a UV absorber,
e.g. benzophenone-4, to protect against color fading and other
reasons upon prolonged exposure to light.
5. Preservatives
Are essential component of a shampoo formulation to protect
against microbial growth.
E.g. parabens.
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Effect of shampoo on hair
Shampoos are also involved in damage of hair, either directly;
through removal of structural components of the hair fibers,
of indirectly; through removal of protective deposits on the
hair.
1.
Direct damage:
Studies indicated that the nonkeratinious regions of the hair,
which include the endocuticle, or inner portion of the cuticle,
and the cell membrane complex are susceptible to damage by
surfactant molecules.
Exposure to shampoos can have deleterious effect on hair
structure over time.
2.
Indirect damage:
It is a result of fiber abrasion occurring when hairs are
rubbed against each other during cleaning. More important is
the removal of sebum from the fiber surface during
shampooing (sebum act as natural lubricant for hair).
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Shampoo benefits
Shampoo formulations are classified into four
basic functions:
Cleaning, mild (or baby), conditioning, and
antidandruff.
‫ ٭‬Mild or baby shampoos is required to allow only
minimal eye, scalp, and skin irritant.
They often contain mild surfactant systems,
such as nonionics and amphotrics.
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Examples of shampoo’s formulas
Cleansing shampoo
Ingredient
%
Ammonium lauryl sulfate
15
Cocamide DEA
2
Cocamidopropyl betain
2
Fragrance
0.7
Preservative
0.5
Citric acid
0.3
Ammonium chloride
0.2
Color
0.001
Water
q.s
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Baby shampoo
Ingredient
%
PEG-80 sorbitan
laurate
12
Sodium trideceth
sulfate
5
Sodium
lauroamphoacetate
5
PEG-120 methyl
glucose dioleate
2
Cocamidopropyl
hydroxysultaine
1
Fragrance
0.7
Preservative
0.5
Color
0.01
Water
q.s
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Conditioners
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Does hair need conditioner?
Conditioners are formulated to impart conditioning to
hair, for example; improve combing, softness, and
manageability, in addition to the usual cleaning
benefits.
Physical damaging effect:
♦ Wind, weather, ultraviolet radiation, brushing and
combing.
Chemical damaging effects:
1. Shampoos which remove natural lipids
2. Dyeing require preliminary bleaching
3. Bleaching with alkaline hydrogen peroxide
Drastic treatment which cause severe weakening of
the hair fibers and loss of elasticity
4. Permanent waving
Where peroxide and thioglycollate attack the
disulphide and peptide bonds of keratin.
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 Conditioning term is difficult to define
The process of conditioning involves at
least four functions:
1.
2.
3.
4.
Rendering the hair manageable, easy to comb and
set.
Preserve its natural appearance and luster.
Exerting a softening effect.
Giving “BODY” to the hair.
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Conditioners ingredients
Emollients
Compounds containing positively
charged nitrogen
Acids
Proteins
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Emollients
Oil adheres to hair fibers → body + luster +
lubrication
Excessive greasiness can be overcome by applying
the lipid in the form of diluted O/W emulsion and
by using high melting point lipids, such as
cetostearyl alcohol.
 Vegetable oil, lanolin and its soluble derivatives
(POE or quaternaries), synthetic esters, sebum
substitutes, Octyl stearates and Squalene
 Silicones have high refractive indices, and are
therefore good luster producing compounds.
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Compounds containing positively charged nitrogen
Keratin contains more acid groups than basic groups,
and therefore tend to attract positively charged
molecules and ions.
1. Cationic compounds (quaternary ammonium
compounds), a typical example → cetrimide
2. Amidoamides (tertiary amines).a typical example →
stearamidopropyl dimethylamine lactate
3. Alkanolamide, example → Coconut diethanolamides
4. Ampholytes, example → N- alkylbetaines as anti
irritant.
5. Polyvinylpyrolidone (PVP).
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Acids
The conditioning effects of weak acids have been
known since ancient times (lemon juice, vinegar)
1.They dissolve calcium and magnesium deposits.
2.Neutralize excess alkali after bleaching or
permanent waving.
3.Precipitate the soluble keratin products resulted
from the rupture of peptide bonds by the action of
peroxide or thiglycollate.
 A suitable lipid mixture is emulsified with cationic
surfactant → O/W and a small quantity of weak
organic acid and protein can be added.
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Proteins
Proteins are actually mixture of:
1.
2.
3.
4.
Proteins
polypeptides
peptide
amino acids
We can prepare them by hydrolyzing protein
usually with enzyme → Collagen, Milk, Oats,
Wheat, Soya.
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Protection of hair treated by protein
Cosmetic process
Bleaching
Waving
without protein
with protein
Cuticle removed
Cuticle intact
Extensive damage
Swelling, but no
damage
Its recommended that protein hydrolsates are used
before, with or after the chemical process.
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Absorption of protein fragments has
been demonstrated in several ways:
1.Treatment with
– methionine was found
to retain radioactivity after rinsing.
2.Stronger color and ninhydrin, transverse
section stained more deeply
3.Hydroxyprolin of collagen ( analysis)
Undamaged
Absorbed
Moderately
bleached
Bleached
water
0.08%
0.2%
3.0%
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Example of conditioner formula
Ingredient
concentration %
Primary surfactant
12-20
Dehydrogenated tallow Phthalic
acid amide
4-7
Dimethicone
0.5-3
Cocamide DEA
1-5
Miscellaneous
q.s
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