cosmetology zoo

According to Article 1 of the decree of June 30, 2000 (Official Journal of July 12, 2000), the Shampoos are classified as cosmetics under the heading of cleaning products in the hair care products section.

Developing a shampoo requires a careful balance between the base

cleansing agent, formed from a combination of several surfactants, which constitutes the core of the formula,

and all other components (foam stabilizers, thickeners, pearlescent and opacifying agents,

softeners and superfatting agents, sequestering agents, pH adjusters, preservatives, perfumes and

colorants, "active" substances, which give it its physical and "cosmetic" qualities

and can, as needed, modify its performance.

Possessing wetting, detergent, solubilizing, and dispersing properties,

Emulsifying and generally foaming, surfactants are the constituents

The main ingredients of a shampoo are, in a way, its "active ingredient." They represent...

average, in solution, 15 to 30% (weight or volume) of the formula.

PRINCIPLE OF ACTION:

They promote the spreading of water on the surface of the skin and hair, loosening the

dirt, emulsifies it, whether it is hydrophilic or lipophilic, and finally, facilitates its removal

removal by rinsing.

Note: their foaming power, which is in no way related to their detergent capabilities,

However, it allows you to monitor the washing process. Always synonymous with efficiency in

In the consumer's mind, the presence of lather is necessary for them, and for shampoos

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Those that produce little or no foam, even if they are just as effective, are neglected because they are less

pleasant to use.

These are substances that have the power to modify surface properties

bodies at the interface of which they are placed, thanks to their amphiphilic structure comprising

a hydrophilic part and a lipophilic part.

Surfactants can be of natural origin (lecithins, sterols, saponins:

extracted from Panama wood (Quillaya saponaria, Rosaceae) or soapwort (Saponaria

officinalis, Caryophyllacea). Plant saponins are experiencing a resurgence of interest.

Excellent detergents (not too harsh), they leave no residue on the skin and do not

They do not cause any reactive seborrhea, which allows for their intensive use. One can

However, they are criticized for their lack of foaming.

But the most commonly used ones are synthetic.

These are classified into four main families, according to their mode of ionization in

Water. We can thus distinguish:

• anionic compounds, whose hydrophilic part ionizes with the formation of a charge

negative;

• cationic, which ionize with the formation of a positive charge;

• Amphoteric compounds, which ionize differently depending on the pH of the solution: in

In a basic environment, they exhibit anionic character, and in an acidic environment, a

cationic character;

• non-ionic, which do not ionize.

A shampoo formula always contains a combination of several

surfactants from different families because no single surfactant possesses all the

required properties.

Anionic surfactants

Anionic surfactants are widely used in the formulation of shampoos, including

They generally represent the base, at rates varying from 10 to 30%, most often

combined with an amphoteric surfactant (which improves their foaming power in hard water and their

tolerance) and/or non-ionic.

The following are employed:

• Alkyl sulfates: sodium lauryl sulfate, ammonium lauryl sulfate, triethanolamine,

of isopropanolamine… . An American study involving 438

shampoos showed that 24.4% of shampoos contain

sodium lauryl sulfate, 27.2% of ammonium lauryl sulfate and 22.4% of

triethanolamine lauryl sulfate;

• Alkyl ethers sulfates: sodium lauryl ethers sulfate, ammonium lauryl ethers sulfate,

triethanolamine, sodium laurylmyristyl ether sulfate….The same study (12)

that previously showed that 20.1% of shampoos contain

sodium lauryl ether sulfate;

• sulfonates: sulfosuccinates, fatty acid sulfonamides, acylisethionates,

alpha-olephin sulfonates…;

• Carboxylates: derivatives of amino acids (acylsarcosinates, acylates of

collagen or various other proteins from wheat, oats, corn, soy…),

polyoxyethylenated carboxylic acid salts… .

Note: soaps are no longer used in shampoos because, on the one hand, they

are very alkaline; on the other hand, they form with calcium and magnesium ions, contained in

a significant amount in hard water, insoluble salts that dull the coat and the

make it rough and difficult to brush (especially in long-haired dogs).

In general, anionic surfactants are good detergents (they possess a strong

affinity for dirt, positively charged; moreover, having no affinity for

Keratin, being negatively charged, does not redeposit on the hair and is perfectly

eliminated by rinsing), good foaming agents (although their foaming power is altered in

presence of hard water) and are inexpensive; they are sensitive to pH and exhibit

numerous incompatibilities with cationic 'surfactants'; some are irritating and

leave the fur too dry and difficult to brush.

Sulfonates and carboxylates, on the other hand, have very good tolerance.

Our preference is for carboxylates and, in particular, among them, lipoamino acids:

very mild cleansers with an acidifying character, lipoamino acids (palmitocystinic acid,

collagen acids…) are used in the composition of various intensive use shampoos.

In addition to their cleansing properties, lipoamino acids have the following properties:

o normalization of skin pH, by improving buffering capacity,

significant foaming property,

o no reactive seborrhea. Some shampoos cause after

usage leads to an exacerbation of the functioning of the sebaceous glands: this is

what is called reactive seborrhea. In a way

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In general, the more often the dog is washed with this type of shampoo, the faster the

skin becomes oily;

o deposition of a lipoprotein film, which remains after rinsing.

Cationic surfactants

Highly substantial for keratin (because they are positively charged), they possess

bacteriostatic and fungistatic properties are utilized in the formulas.

anti-dandruff agents. Their affinity for hair, however, means they are mainly used as

Conditioners and film-forming agents: they are thus presented as coating and detangling agents.

They allow the hair cuticle to smooth (by remaining in film form on the hair, they seal

the scales (or prevent them from separating), restoring its softness and shine and

They make brushing easier. However, this affinity for hair makes them difficult to remove.

The following are used in particular:

• Quaternary ammonium salts:

o short-chain: benzalkonium chloride, chloride of

cetylpyridinium chloride, cetyltrimethylammonium chloride, chloride of

dimethylphenylammonium…;

o long-chain: quaterniums, polyquaterniums…; the more you increase the

The longer the 'fat chain', the greater the 'smoothness' effect.

The American study (12) showed that 18.3% of shampoos

contain quaternium-15 and 12.6% contain quaternium-19;

• amine salts: octadecylamine hydrochloride…, etc.

They are used in proportions ranging from 5 to 10%, generally associated with

Amphoteric and non-ionic surfactants, particularly in certain medicated shampoos

(anti-squamous).

Many are irritating, even aggressive and harsh; they are also bad

detergents (because they are positively charged like dirt) and poor foaming agents: they do not

Therefore, they do not constitute the cleansing agent in a shampoo but contribute to improving the

hair surface. They are pH sensitive and incompatible with surfactants

anionic. However, cationic polymers have brought a breakthrough to this field

Notable improvement: their particular structure and the low concentrations used (0.5 to

1%) allow them to be associated with anionics.

Amphoteric surfactants

Also called ampholytes, they have the particularity of behaving differently

depending on the pH of the solution: below their isoelectric point, that is to say at a higher pH

acidic, they are cationic and compatible with cationic acids; above, at a more alkaline pH,

They are anionic and compatible with anionic substances. At their isoelectric point, they are at the

both carry positive and negative charges and are therefore compatible with all others

surfactants.

Among the most commonly used are:

• Betaine derivatives:

o alkylbetaines (laurylbetaine, cocobetaine…),

o alkylamidobetaines (laurylamidobetaine, etc.),

o alkylamidopropyl betaines (laurylamidopropyl betaine,

cocoamidopropyl betaine…),

o sulfobetaines (laurylhydroxysulfobetaine,

laurylamidohydroxysulfobetaine…);

• Imidazoline derivatives:

o alkylamphoacetates (disodium cocoamphodiacetate…),

o alkylpolyaminocarboxylates (carboxymethyl coco polypropylamine

sodium, sodium carboxymethyl oleyl polypropylamine);

• Alkyl polypeptides: obtained by the action of an acid chloride on

protein hydrolysates or amino acids

(alkylamidopropyldimethylamino polypeptide…).

They are low in irritants, have good foaming and detergent properties, are stable and

possess a slight conditioning power.

The cost price is relatively high. They are generally used at rates of

the range of 5 to 15%.

They are frequently associated with anionic compounds, whose foaming power they enhance.

in hard water and skin and eye tolerance. They are also widely used in

shampoos for frequent use (as well as baby shampoos for humans).

Non-ionic surfactants

They are good solubilizers, emulsifiers, wetting agents, and dispersants. Their

Foaming performance is generally limited, they are weak detergents, and they do not

are not substantive for keratin.

Among the most commonly used:

• polyoxyethylene glycol esters (PEG stearate…),

• sorbitan esters, polyoxyethylenated sorbitan esters (polysorbates),

• sucrose esters or sucro-esters (sucrose distearate,

sucrose monodistearate, sucrose monopalmitate…),

• alkylpolyglucosides (decylglucoside, laurylglucoside, etc.),

• fatty acid amides: (monoethanolamides, diethanolamides,

fatty acid isopropanolamides). The American study (12) showed that 42.2%

shampoos contain lauramide DEA and 30.4% contain

cocamide DEA

Relatively expensive, they are generally used as secondary 'surface agents' or

'co-surfaced'.

Being compatible with other surfactants, they are often combined with them (at a rate of

5 to 15%), which helps to reduce the level; active, regardless of pH, they are less

irritants than ionic 'surfactants'.

They improve the qualities of shampoos in the presence of calcium salts and facilitate

Rinsing. Combined with cationic agents, they improve the detergent power of the shampoo.

A symbol of cleanliness, foam is one of the characteristics of shampoos that...

users appreciate it the most, believing it to be inherent to their efficiency, which is not

True. That being said, the foam does allow you to follow the washing process, a peeling

dirty, rich in sebum, causing a significant reduction in lather.

Its qualities are assessed according to various criteria, including its training speed,

its development, its density, its viscosity, the size of the bubbles, its stability, its ease

elimination. They are strongly influenced by the structure of the surfactants chosen.

The addition of foam stabilizers helps to improve its firmness and smoothness.

They also often act as 'superfatting' and softening agents.

This is achieved using certain non-ionic surfactants such as fatty acid amides:

monoethanolamides, diethanolamides, fatty acid isopropanolamides, in particular

copra, but also certain amphoteric and polymeric compounds, at levels of around 3 to 4%.

They increase the viscosity of the shampoo to make it easier to apply.

They also alter the texture, appearance, and feel of the product. They are used

generally at concentrations ranging from 2 to 10%. They are chosen not only by

depending on the parameters described above, but also according to technical criteria:

compatibilities, particularly with the selected surfactants, pH of use, resistance to

suspension, ability to prevent redeposition of soiling, etc.

Depending on the case, they may be:

• Electrolytes: sodium chloride, magnesium chloride, ammonium chloride, sulfate

ammonium…;

• Naturally derived polysaccharides: guar gum, tragacanth gum, xanthan gum,

alginates, carrageenates, etc.;

• cellulose derivatives: methylcellulose, hydroxyethyl or

hydroxymethylcellulose, carboxymethylcellulose… . The American study (12) has

showed that 18.7% of shampoos contain

hydroxypropylmethylcellulose;

• carboxyvinyl polymers;

• polyvinyl alcohols and polyvinylpyrrolidones;

• Alkanolamides (fatty acid amides): monoethanolamides,

diethanolamides, fatty acid isopropanolamides… .

They alter the appearance of shampoos, giving them a creamier look and

a precious quality that helps establish or reinforce the product's image. Pearlescent coating can

also allow to mask a disorder caused by certain components of the formula.

This pearly effect is caused by waxy-looking substances that are dispersed

in surfactants and whose particles, which are in the form of flakes or

Crystals reflect light.

These are primarily fatty alcohols such as cetyl alcohol, stearyl alcohol, and

fatty acid alkanolamides, monoesters or diesters of ethylene glycol… which are

They are used. They often also act as fabric softeners.They are added to a

concentration of approximately 1%.

Their role is to make brushing easier after shampooing, and to give the coat shine

and softness (which is not recommended for wire-haired dogs).

We use:

• Fatty acid derivatives: alcohols or fatty esters,

• Lanolin and its derivatives: lanolin alcohol, acetylated derivatives, lanolin

oxygenated…,

• vegetable oils: sesame, wheat germ, corn, calophyllum…

• animal oils: mink…,

• vegetable waxes: jojoba…,

• humectants: glycerol, sorbitol, propylene glycol. The American study (12) has

showed that 21.9% of shampoos contain propylene glycol;

• protein hydrolysates The same study (12) showed that 37.9% of

shampoos contain hydrolyzed animal proteins.)

• cationic polymers,

• lecithins and their derivatives.

Their concentration varies from around 1 to 5%.

Added at levels close to 0.1%, they complex with calcium and magnesium ions

present in rinsing water to prevent the formation of insoluble salts that alter

the quality of the lather and dull the hair. The most commonly used are salts of

ethylenediaminotetraacetic acid (EDTA) or sodium hexametaphosphate.

The skin is an integral part of the immune system because it contains, in a way,

constant of elements specific to the immune system (macrophages, lymphocytes, …),

but also because its own cells are capable of actively participating in

development of inflammatory reactions.

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Their role is to inhibit the growth of bacteria and yeasts and to prevent the

fermentations. The most commonly used are parahydroxybenzoic acid esters (parabens),

sorbic acid, imidazolidinyl urea, phenoxyethanol, methylisothiazolinones and

methylchloroisothiazolinone (the American study (12) showed that 54.8% of shampoos

contain methylparaben and 35.6% propylparaben). They are generally used in

predefined associations, so as to cover the broadest possible spectrum of activity

as well as a significant pH scale. They are added at concentrations close to

0.1%, but they must be chosen wisely because many of them can be

inactivated by 'surfactants'.

Antioxidants (tocopherols, etc.) are only used if the formula contains

easily oxidizable lipids.

They give the shampoo its character, both olfactorily and visually,

giving it a pleasant smell and appearance. The appearance is solely the owner's prerogative.

The scent is pleasant to both the owner and the dog.

The scent must be acceptable to the animal; that's why we will avoid all perfumes.

citrus peels (lemon, orange) are very pleasant for the owner but repellent for

the animal. We have very little information regarding the scents that animals prefer.

dogs. The manufacturers who use these substances keep it secret for reasons

commercial.

Their choice depends not only on their qualitative criteria and stability,

but they must also preserve the stability of the base in which they are incorporated.

as well as its physicochemical characteristics: viscosity, solubility, pH. Their compatibility

with the other components, including the packaging, is taken very seriously

taken into account. Perfumes are most often solubilized thanks to the presence of surfactants.

They are used at concentrations of around 0.1%.

These active substances are added to formulas to give them properties

specific. They are particularly numerous and are grouped into several subgroups:

• Keratolytic agents: they reduce the thickness of the stratum corneum and

eliminate the scales, which is particularly beneficial in cases of disorders of

Keratinization (seborrhea). Salicylic acid is a major keratolytic agent.

which acts by lowering the pH and increasing the amount of absorbable water

through keratin: the stratum corneum softens and is easily shed. It is

It is frequently associated with sulfur because there is a synergy between their actions. It is

more bacteriostatic.

• Keratoregulatory agents: they reduce the rate of cell division

germinal cells of the basal layer during excessive acceleration of their

renewal. Purified coal tar is the leader in

keratolytic agents, and the most used in veterinary dermatology, but it presents

The major drawback is that it is too aggressive and can cause seborrhea.

rebounds. Its use in humans is prohibited by law.

European since June 30, 1999 because it contains hydrocarbons

Polycyclic aromatic hydrocarbons (including benzopyrene), known carcinogens

genotoxic substances, in very high concentrations, whether crude or refined.

Low-benzopyrene tars are being developed to replace it.

Cade tar and ichthyol exist: the latter is used as

keratoregulatory agent in human dermatology and due to its very high

tolerance, it can be used in dogs against dry seborrhea or

fats.

• Anti-seborrheic agents: they reduce sebaceous production and

Secondarily, the blockage of the hair follicle. Sulfur is classified as

anti-seborrheic. Its anti-seborrheic activity is currently considered

is real but poorly explained. Its frequent use should be reserved for cases of

Oily seborrhea because it can cause irritation and sebaceous secretions

rebounds.

Among other things, we have:

• Anti-seborrheic shampoos: characteristics and needs

Oily coats are the focus of these shampoos' formulations:

o an effective but gentle detergent action (amphoteric and non-ionic,

particularly polyglycol derivatives [which slow down the

regreasing], Quillaya extracts rich in saponins…) in order to eliminate

excess sebum without causing lipid depletion

excessive which could be a source of reactive seborrhea, and without

to further irritate the skin,

o the incorporation of substances intended to regulate sebum flow, to

to slow its migration onto the coat (cedar essential oil, acids)

sulfur amino acids, various plant extracts [nettle…], vitamin B6,

astringents, sebum-regulating agents…) and to cleanse the skin in such a way as to

to avoid excessive microbial growth (essential oils)

antiseptics…),

o an absorbent function of sebum (clays…).

• Anti-dandruff shampoos: to eliminate flakes

and to prevent or limit their recurrence, shampoo formulas must

include:

a gentle yet sufficiently effective detergent base to remove

adherent scales and are completely harmless to the skin which is already

very disturbed,

o bactericides and fungicides to limit proliferation

microbial (piroctone olamine, zinc pyrithione, derivatives)

undecylenic acids, various antiseptics including quaternary ammonium compounds…),

o active ingredients that slow down cell renewal

(keratolytic agents: cade oil, ichthammol derivatives…) and which

eliminate scales (keratolytic agents such as salicylic acid…),

o anti-inflammatory and soothing substances (Aloe Vera, extract)

(Chamomile, oat colloid, etc.) to soothe itching

frequently associated with these conditions.

The manufacturing process typically involves three stages. :

The first step is to mix the water-insoluble components.

(methylparaben, propylparaben, jojoba oil) with propylene glycol.

The second step involves incorporating the previous mixture into the purified water.

preheated to facilitate dissolution, then, after pH stabilization, to be added

pH-sensitive compounds (ammonium lauryl sulfate).

Volatile substances, such as perfumes, are added once the temperature

falling below 40° Celsius, which constitutes the third and final stage of the

manufacturing.