Basic forms and means used to care for the scalp

Forms intended for cleansing the hair and skin of the scalp

To cleanse the scalp, the main thing is the form of the shampoo. Now for this purpose, soaps are used less often. In most cases, they are used to achieve a therapeutic effect. So, some soaps are prescribed for skin and hair care in seborrhea, seborrheic dermatitis, psoriasis, ichthyosis. Existing dosage forms of powder (powder), cream, aerosol and oil solution for hair cleansing are practically not used.

Composition

In principle, the composition of any shampoo includes water, detergent (surfactant, surfactant) and various obesity supplements. As a detergent used soaps of different origin, as well as synthetic compounds. The composition of the detergent plays an important role. They are distinguished by the following varieties:

• Anionic (anionic) detergents are surfactants (surfactants), molecules of which dissociate in water to form a foam of surface-active long chain anions. Alkaline, metallic and organic soaps obtained by alkaline hydrolysis of fats are referred to as anionic detergents. The raw materials for the production of soap are vegetable oils, animal fats, synthetic fatty acids, soap, salomass, rosin, waste from the refining of fats and oils. The process of obtaining soap (soap making) consists in saponification of the initial fats with an aqueous solution of alkali during boiling. When the saponification of fats with potassium alkali results in liquid, with sodium - solid soaps. Most often shampoos include anionic detergents.
• Cationic (cationic) detergents - surfactants, molecules that dissociate in solution to form a surface active cation - a long hydrophilic chain. Cationic surfactants include amines and their salts as well as quaternary ammonium compounds. Cationic detergents are less effective than anionic detergents, since they reduce the surface tension to a lesser degree, but they can interact chemically with the surface of the adsorbent, for example, with bacterial cell proteins, causing bactericidal action. That is why cationic detergents are used as antiseptics. Cationic detergents are used as an additive in hair care products after washing.
• Nonionic (non-ionic) detergents (syndets) are surfactants that do not dissociate in water into ions. Their solubility is due to the presence in the molecules of hydrophilic ether and hydroxyl groups, most often a 2-polyethylene glycol chain. They are less sensitive to salts that determine water hardness than anionic and cationic detergents, and are also well compatible with other surfactants.
• Amphoteric (ampholytic) detergents are surfactants containing in the molecule a hydrophilic radical and a hydrophobic part capable of being a receptor or proton donor, depending on the pH of the solution. Usually, amphoteric detergents are used as an emulsifier in the preparation of creams (emulsions).

The composition of the detergent shampoo creates a certain environment on the surface of the skin. So, anionic detergents create alkaline medium (pH = 8-12), nonionic - weakly acid (pH = 5,5-6). Many firms produce neutral shampoos (pH = 7), the acidity of which is due to the two types of detergents that come in at the same time (soap and sindet).

Previously, shampoos were used only to purify the scalp. In the future, due to the addition of certain funds, the range of action of shampoos was slightly extended. Most modern shampoos include conditioners (substances that make it easier to comb the hair), so the most popular in the market today are shampoos, prepared according to the formula "two in one". Some cosmetic companies use various components of a different action in the manufacture of shampoos. So, recently shampoos are widely used, which include natural dyes (chamomile, henna, basma, etc.) to give the hair a certain shade. Shampoos containing ceramides appeared on the market. Laboratoires Phytosolba (France) uses as an additive to shampoo tyrosine derivatives, inhibiting the appearance of gray hair, as well as derivatives of azulene to eliminate the yellowing of gray hair.

In recent years, various medicines have been added to the shampoo. Thus, a whole generation of shampoos, designed to treat superficial lesions of the scalp. They are used to treat seborrhea, seborrheic dermatitis, pityriasis and dermatophytosis, pediculosis, psoriasis, androgenic alopecia and other diseases. The composition of therapeutic shampoos usually include:

• antifungal agents, for example ketoconazole (2%), zinc pyrithionate, tar, sulfur, selenium disulphide;
• pediculocidal means - pyrethrin, piperonyl, phenotrin, tetrametrin, etc .;
• salicylic acid;
• drugs that increase blood flow to hair bulbs - minoxidil (2.5-5%), amineksil (1.5%);
• vegetable oils (from coconut, cypress, rosemary, tea and cayeput trees, etc.).

Mechanism of action

The mechanism of washing action of shampoo is based on emulsification of fats and is similar to that of anionic soaps. Under the influence of water, the soap is hydrolyzed, the free base is freed, which, emulsifying the fat of the pore layer, forms foam, rinses off the exfoliating horny scales and along with them - dirt, dust, microorganisms, skin gland secrets (sebum and sweat). In the washing action of shampoos, the most important is the pricing process, and their degreasing action should be moderate. Included in the shampoo medicinal products, acting keratolytic and anti-inflammatory, contribute to a rapid reduction of peeling and itching of the scalp. With the use of this form, due to the shortness of contact, there is no noticeable absorption of the pharmacological agent by the skin.

Mode of application.

The therapeutic shampoo is applied evenly to damp hair and affected areas of the skin, aged for 3-5 minutes and rinsed off with warm water. Shampoos are usually well tolerated, but there may be sensations of burning, itching, erythema of the scalp, obesity or dryness of the hair.

All shampoos appearing on the market are evaluated for safety and efficacy. Safety of shampoos includes the absence of toxic effects on the body, as well as irritating effects on the skin and conjunctiva. It is known that irritating effects on the skin almost never occur without irritating effects on the eyes. That's why to test the presence of irritating effects in the production of many shampoos, a test, or a Draize sample, is used. The essence of this test is the application of solutions of shampoos in certain dilutions in the conjunctival bag of an albino rabbit. It was found that cationic detergents possess the greatest irritant effect, and anionic ones have a lesser effect. Minimal irritating effects are characterized by nonionic detergents.

Evaluation of the effectiveness of conventional shampoos is very subjective and is based on certain consumer sensations. First of all, lightness of application to hair, foam formation, washing and combing in wet condition are taken into account. After using the shampoo, the presence of hair shine is also determined, the speed of drying, the ease of styling are examined.

[1], [2], [3]