Basic forms and products used for scalp care

Forms designed for cleansing hair and scalp

The main form of cleansing the scalp is shampoo. Nowadays, soaps are used much less often for this purpose. In most cases, they are used to achieve a therapeutic effect. Thus, some soaps are prescribed for skin and hair care in cases of seborrhea, seborrheic dermatitis, psoriasis, and ichthyosis. The existing medicinal forms of powder, cream, aerosol, and oil solution for cleansing hair are practically not used.

Compound

Basically, any shampoo contains water, detergent (surfactant) and various fattening additives. Soaps of various origins, as well as synthetic compounds, are used as detergents. The composition of the detergent plays a significant role. The following varieties are distinguished:

• Anionic (anionic) detergents - SAS (surface-active substances), the 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 classified as anionic detergents. Raw materials for soap production are vegetable oils, animal fats, synthetic fatty acids, soap naphtha, salomas, rosin, waste from refining fats and oils. The process of obtaining soap (soap making) consists of saponification of the original fats with an aqueous solution of alkali during boiling. When saponifying fats with potassium alkali, liquid soaps are obtained, with sodium alkali - solid soaps. Most often, shampoos include anionic detergents.
• Cationic (cationically active) detergents are 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 ones, since they reduce surface tension to a lesser extent, but they can interact chemically with the surface of the adsorbent, for example, with bacterial cellular proteins, causing a bactericidal effect. This is why cationic detergents are used as antiseptics. Cationically active detergents are used as an additive in hair care products after washing.
• Nonionic (nonionogenic) detergents (syndets) are surfactants that do not dissociate into ions in water. Their solubility is due to the presence of hydrophilic ether and hydroxyl groups in the molecules, most often along the 2-polyethyleneglycol chain. They are less sensitive to salts that cause water hardness than anionic and cationic detergents, and are also well compatible with other surfactants.
• Amphoteric (ampholytic) detergents are surfactants that contain a hydrophilic radical and a hydrophobic part in the molecule, which can be a receptor or a proton donor, depending on the pH of the solution. Amphoteric detergents are usually used as an emulsifier in the manufacture of creams (emulsions).

The composition of the shampoo detergent creates a certain environment on the skin surface. Thus, anionic detergents create an alkaline environment (pH= 8-12), nonionic - slightly acidic (pH=5.5-6). Many companies produce neutral shampoos (pH=7), the acidity of which is due to the two types of detergents included in their composition at the same time (soap and syndet).

Previously, shampoos were used only for cleaning the scalp. Later, by adding certain agents, the range of action of shampoos was somewhat expanded. Most modern shampoos contain conditioners (substances that facilitate combing hair), so the most popular on the market today are shampoos prepared according to the "two in one" formula. Some cosmetic companies use various components of a different action when making shampoos. Thus, recently shampoos have become widespread that include dyes of natural origin (chamomile, henna, basma, etc.) to give hair a certain shade. Shampoos containing ceramides have appeared on the market. Laboratoires Phytosolba (France) uses tyrosine derivatives as an additive to shampoo, which slow down the appearance of gray hair, as well as azulene derivatives to eliminate yellowness of gray hair.

In recent years, various medicinal agents have been added to shampoo. Thus, a whole generation of shampoos has appeared, intended for the treatment of superficial lesions of the scalp. They are used to treat seborrhea, seborrheic dermatitis, pityriasis versicolor and dermatophytosis, pediculosis, psoriasis, androgenic alopecia and other diseases. The composition of medicinal shampoos usually includes:

• antifungal drugs, such as ketoconazole (2%), zinc pyrithione, tar, sulfur, selenium disulfide;
• pediculocidal agents - pyrethrin, piperonyl, phenothrin, tetramethrin, etc.;
• salicylic acid;
• drugs that increase blood supply to hair follicles - minoxidil (2.5-5%), aminexil (1.5%);
• vegetable oils (from coconut, cypress, rosemary, tea and cajeput trees, etc.).

Mechanism of action

The mechanism of the washing action of shampoo is based on the emulsification of fats and is similar to that of anionic soaps. Under the influence of water, soap hydrolyzes, freeing the free base, which, emulsifying the fat of the stratum corneum, forms foam, washes away the peeling horny scales and with them - dirt, dust, microorganisms, secretions of the skin glands (sebum and sweat). In the washing action of shampoos, the most important is the process of foaming, and their degreasing action should be moderate. The therapeutic agents included in the shampoo, acting keratolytically and anti-inflammatory, contribute to the rapid reduction of peeling and itching of the scalp. When using this form, due to the short-term contact, there is no noticeable absorption of the pharmacological agent by the skin.

Method of application.

The medicated shampoo is applied evenly to damp hair and affected areas of the skin, kept for 3-5 minutes and washed off with warm water. Shampoos are usually well tolerated, but may cause burning, itching, erythema of the scalp, greasiness or dryness of the hair.

All shampoos appearing on the market are assessed for safety and effectiveness. The 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 is why a test, or Draize test, is used to check for irritating effects in the production of many shampoos. The essence of this test is to apply shampoo solutions in certain dilutions to the conjunctival sac of an albino rabbit. It has been found that cationic detergents have the greatest irritating effect, anionic detergents have a lesser effect. Nonionic detergents are characterized by minimal irritating effects.

The evaluation of the effectiveness of conventional shampoos is very subjective and is based on certain sensations of the consumer. First of all, they take into account the ease of application to the hair, the formation of foam, rinsing and combing in a wet state. After using the shampoo, they also determine the presence of shine in the hair, examine the drying speed, and the ease of styling.

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