cosmetology

Detergents and Detergents

What does Cleanse mean?

The verb "to clean" has Latin origins and literally means "to remove dirt or harmful substance". The dirt, present on the skin and hair, is made up of tissue debris, detached corneal cells and sebum and sweat secretions, to which environmental dirt is added.

Every cosmetic product formulated to perform the hygienic function of cleaning the skin, hair, mucous membranes and teeth is defined as a detergent. In the most advanced societies, the use of products for cleansing the skin and hair is constantly increasing.

In fact, it represents a fundamental requirement for the balance of the body, for health, and therefore for the beauty of the skin.

Detergents

Detergence, as mentioned in article 1 of European legislation, constitutes the first cosmetic act.

If from the physiological point of view the skin would need to be washed only with simple running water, smog, dust and housework are conditions that make hygienic action necessary. It should be remembered, however, that skin cleansing should not be carried out excessively and with too high amounts of detergents, perhaps aggressive, as this could imply a more or less accentuated alteration of the normal defenses of the skin, represented mainly by the skin's hydrolipidic film and from the stratum corneum, with consequent formation of irritative phenomena against the skin, starting with irritative dermatitis, with the possible onset of allergic contact dermatitis.

Skin cleansing must therefore be carried out according to appropriate rules, in order to maintain its homeostasis and guarantee the physiological functions of its components. A good detergent product requires the ability to clean the skin thoroughly but without drying it and irritating it, to perform an emollient action, not to cause redness, cracking and allergies of any kind.

Evolution of Detergents

The awareness that too strong a cleansing can cause harmful effects on the skin, together with the greater attention on the part of the cosmetic formulator towards the toxicology of substances and their degree of irritation, has led, in recent years, to the substantial change of the composition which quantitative of detergent products. If originally these products contained only viscosylated alkyl sulphates with electrolytes or alkanolamides and some additives, today, the cosmetic formulator has new substances available with a delicate cleansing action and a remarkable variety of additives that allow a less aggressive and more physiological washing.

In addition, modern cosmetology, faced with the increasingly felt problem of "poisoning the planet" also due to substances, in particular stress-relieving substances, which are not easily biodegradable, is moving, with increasing conviction, towards molecules of natural origin and more biocompatible. At the base of a detergent product there are surfactants, substances of an amphiphilic nature which, acting on the surface tension (force present at the contact between water and air) and on the interfacial tension (force present at the contact between two liquids), facilitate all the phenomena of bagability, emulsification and removal of fatty substances, which by their nature are not very close to water. In this regard, it should be emphasized that there are two types of cleansing, a so-called "by affinity" and a "by contrast":

  • the former does not require surface-active substances and occurs when the oily dirt is removed with oil, which can easily remove substances related to it;
  • the second occurs when a surfactant is used which, at the time of washing, is arranged with the lipophilic tail towards the dirt and the hydrophilic head towards the water forming micelles that absorb the dirt, which comes off in the form of a drop .

Today, many affinity cleaners are available, such as oily shampoos or make-up removers. Cleansing is the most common phenomenon through which this process of removing dirt from the skin surface takes place and changes depending on whether we are faced with oily, dry or sensitive skin, or if it is aimed at cleansing the skin of an elderly or of a child.

Skin Type Cleansers

  • Dry skin should be cleansed with delicate, low-foaming products that do not alter the hydro-lipid barrier of skin protection and preferably without fragrance, for example you can use cleansing milks, formulated with a moderate content of fatty phase, even with vegetable oils.
  • Sensitive skin, like that of the elderly, requires the use of non-foaming detergents, characterized by few ingredients, possibly without perfume and with an emollient action.
  • Even if oily skin is not easy to normalize, as the sebaceous activity is under hormonal control, therefore scarcely influenced by cosmetics, it still needs daily deep cleaning, an operation for which rinsing detergents are preferable to "cleansing milk" which, by containing fatty bodies, could be comedogenic.

For even more thorough cleaning, you can also resort to more intensive treatments, such as clay, bentonite and kaolin based masks, or exfoliating products, characterized by the presence of polyethylene microspheres, hazelnut granules or substances with smoothing and restorative action such as salicylic acid or glycolic acid which, by eliminating impurities, make it possible to obtain a smoother and brighter skin.

Astringent products are preferable to those too degreasing, which can worsen the situation by inducing an even greater stimulation of the activity of the sebaceous glands.

Child cleaners

The baby's skin, on the other hand, requires very delicate, fragrance-free products, based on naturally derived surfactants, with little foam and easily rinsed. Among the most employed, the alkylpolyglucosides, the condensates between fatty acids and proteins and the acylglutamates, all well tolerated and skin-compatible. Interesting the use of anfoacetates, amphoteric surfactants, as inhibitors of adhesion of bacteria to the skin.

The typical products for cleansing baby's skin are characterized by maximum delicacy and hypoallergenicity, in order to respect the acidity of the skin and its structure, and can be divided into:

  • cleaning oils
  • detergent emulsions
  • neutral shampoos

The cleaning oils used in cosmetic products can in turn be divided into two categories:

  • the so-called "dispersible" ones, mixtures of oils and surfactants which, poured into the water of the tank, form a milky emulsion in situ,
  • and those that cannot be emulsified, whose function is very delicate cleansing, with emollient and moisturizing effects due to the veil of residual oil that remains on the skin.

In general, if we consider the index of skin irritation, detergent emulsions are less aggressive than foaming detergent solutions or gels, although they are formulated with delicate surfactants, since they remove dirt with an emulsification and not solubilization mechanism as it occurs for tensoractivated systems, less destructuring towards barrier lipids. However, it is important that the emulsifiers are present in the formula in the minimum amount necessary, since, being amphiphilic substances, they can act as carriers for penetration of the emulsified substances, proportionally to their concentration.

The shampoo intended for children must be a product formulated with particularly delicate surfactants with low eye irritation, so it is preferable to have pH values ​​close to those of the tear fluid (about 7), to avoid burning in case of contact with the eyes.

Detergents products

In the dermocosmetic market there are three types of detergent products:

  • Classic soaps in solid form
  • Syndet in solid form
  • Fluid cleaners

Then see the in-depth information relating to:

  • gel douche
  • Shower gel
  • Intimate cleansers