External agents in cosmetology

Main dosage forms and products in dermatocosmetology

External preparations used in cosmetology serve the same purposes as those used in dermatology:

1. Elimination of the cause of the disease (etiological therapy).
2. Elimination of pathological changes in the skin (pathogenetic therapy).
3. Elimination of subjective sensations (symptomatic therapy).
4. Skin protection.

At the same time, the need to solve aesthetic problems somewhat expands the indications for prescription and makes some additions to the specified points. External etiologic therapy is widely used, for example, antimicrobial - for pyoderma, papulopustular acne, pustular rosacea, fungicidal - for dermatophytosis and seborrheic dermatitis, antiparasitic - for scabies and lice. Agents that affect the links of pathogenesis are used for acne, procoma, allergic, perioral, atopic dermatitis, psoriasis and other dermatoses.

However, external therapy is more often symptomatic and is aimed at eliminating and resolving pathological changes in the skin and the subjective sensations that accompany them. If in dermatology a specialist chooses therapy with a predominant effect on such subjective symptoms as itching, burning, paresthesia, then in cosmetology other complaints are also taken into account: a feeling of "tightness" of the skin, oily shine, pale skin color, a feeling of "flushes" to the surface of the skin, etc. In some cases, external therapy is prescribed to protect the affected skin layers from the effects of external irritants. Thus, in dermatology, a paste is used to protect the skin around an ulcerative defect or around an area where products with a high concentration of keratolytics and other destructive ingredients are applied. In cosmetology, photoprotective agents are widely used to protect the skin, as well as products with antiradical activity. The use of aniline dyes and traditional tar and ASD in dermatology is significantly limited in cosmetology due to the persistent color of the former and the specific smell of the latter.

The stated goals are achieved by using pharmacological agents of external therapy in various forms. In cosmetology, both classical pharmacological agents of external therapy and some herbal and synthetic ingredients are used, designed to solve a number of aesthetic problems (cosmetics included in the composition of cosmetic products). Pharmacological agents are divided into indifferent and those with a certain pharmacological effect. Indifferent agents, which have an effect only due to their physical properties, include: water, chemically neutral powdered substances, oils, fats, fat-like substances, gels, collodions. They usually form the basis of various forms.

In traditional dermatology, the following dosage forms are most often used: solution, powder, shaken suspension, gel, paste, aerosol, cream, ointment, varnish, plaster.

A solution is a liquid medicinal form obtained by dissolving solid or liquid medicinal substances in a solvent. Distilled water or ethyl alcohol are usually used as a solvent. The solution is used in the form of lubrication, wiping, lotions, wet-drying bandages and warming compresses. For lubrication and wiping, aqueous and alcohol solutions of disinfectants and antipruritic drugs are used. In cosmetology, solutions for cleansing and toning the skin are widely used. In such cases, synthetic detergents, acids, disinfectants, moisturizers and other substances are added. In recent years, preference has been given to skin cleansing and toning products that do not contain alcohol. In body cosmetology, solutions are used for wiping large areas of the skin. The addition of moisturizing agents, preparations that stimulate blood circulation and lipolysis allows the use of such solutions in the complex correction of manifestations of gynoid lipodystrophy (cellulite) and obesity.

Powder (talc) - chemically neutral fine powders of mineral (zinc oxide, talc, calamine - a mixture of zinc oxide and iron oxide) and plant origin (various starches - wheat, potato, rice, etc.). Powder has high hygroscopicity, absorbs sweat and sebum, drying and degreasing the skin surface. As a result, evaporation increases and the skin cools. This causes vasoconstriction and a decrease in inflammation and itching. The action of powders is superficial, so they are prescribed for superficial inflammatory processes without weeping, increased sebum and sweating, itching and burning, localization of lesions in folds (diaper rash). In cosmetology, powders are most often used to degrease and dry the skin with hypersecretion of sebum, as well as to fix makeup (loose and compact powders). Powders produced industrially are distinguished by their particularly fine dispersion. Since the powder easily falls off the skin surface, it should be applied several times a day. In cosmetology, the powder form is also used as a drying mask, for example, for seborrhea and acne. It should be remembered that powders dry out the skin, they are contraindicated in inflammatory processes accompanied by weeping, since crusts and lumps are formed when mixed with exudate.

Shake suspensions are suspensions of indifferent powders in water or oil. They are indicated for acute and subacute inflammatory processes not accompanied by oozing. The main components of the water suspension ("chatter") are indifferent powders (30%) suspended in water with the addition of glycerin 10-20%. Oil suspension ("zinc oil") is a suspension of zinc oxide (35-40%) in vegetable oil. In cosmetology, shake suspensions are used as masks. In this case, water suspensions are prescribed for oily skin, oil suspensions - for dry skin. Depending on the tasks of the manufacturer, such masks can be ready for use or released in the form of two substances (powder and liquid), they are prepared ex tempore. For the treatment of seborrhea and acne, water-alcohol shaken suspensions are also used, which include glycerin (5-10%), ethyl alcohol (40-50%), distilled water (40-50%) as a base, and precipitated sulfur, keratolytics, and disinfectants as a means.

Gel (jelly). Hydrogels, which are a colloidal dosage form, are more often used in dermatology. The gel has a gelatinous consistency that can retain its shape and is elastic and plastic. In terms of the mechanism of action, hydrogels are similar to a chatterbox, and in terms of consistency - to an ointment free of fats. Hydrophilic substances (gelatin, agar-agar, gum arabic, etc.) that swell in water to form a colloidal system are used to make gels. In recent decades, acrylates, silicone derivatives, have been included in the composition of the industrially manufactured gel base. Gels include various pharmacological agents (glucocorticosteroids, fungicides, antibacterials, etc.), which quickly penetrate the skin. In cosmetology, gels are used for daily basic care of oily and combination skin. Gels with the addition of cyanoacrylates have the ability to penetrate deep into the sebaceous-hair apparatus and thicken during exposure. It is on the basis of such gels that masks for the face with oily, large-pored skin with comedones are made

Paste is a medicinal form of doughy consistency, containing 50% of indifferent powders and dense fat-like substances or fat (petroleum jelly, lanolin, lard). It has a drying and anti-inflammatory effect, due to the powders included in its composition. It softens the stratum corneum, increasing its permeability for medicinal substances introduced into the paste, softens scales and crusts, facilitating their removal, and mechanically protects the skin from external irritants, due to the fats included in its composition. The paste is used for subacute inflammatory processes that are not accompanied by weeping. The paste should not be used on areas with thick hair. In cosmetology, both face and body, the paste form is used for masks. Just like shaken suspensions, they can be produced ready-made, or they can consist of two separate substances that need to be mixed immediately before applying the mask. The convenience of this method of mixing is that the cosmetologist can adjust the thickness of the applied form depending on the patient's skin type. Traditionally, the skin surface is cleaned from the paste with any vegetable oil, and in cosmetology - with the help of a cleansing emulsion or solution.

Aerosol - is a dispersion system consisting of a gas medium and liquid or solid particles in a suspended state. The aerosol is under pressure in a hermetically sealed container with a valve and a sprayer. The mechanism of action is determined by the properties of the pharmacological agent in the solvent. After spraying, the solvent promotes rapid penetration of the pharmacological agent into the superficial layers of the skin and evaporates. Therefore, the surface action of the aerosol largely depends on the medicinal substances it contains, which have anti-inflammatory, antimicrobial, analgesic and epithelializing effects. Aerosols can be applied to folds, as well as to weeping, erosive lesions. In cosmetology, the aerosol form is used in the manufacture of aftershave foams and post-depilatory care products, including for the bikini area.

Cream (emulsion ointment) is a dense or liquid emulsion dosage form consisting of fat or a fat-like substance mixed with water in a ratio of 2:1 or less. Liquid emulsions of the "oil in water" type (where fat droplets are distributed in liquid) and fatty creams or emulsions of the "water in oil" type, which are formed as a result of dispersion of water in a fat medium, are used. The water included in the cream evaporates, cooling the skin, causing narrowing of blood vessels and causing an anti-inflammatory effect. Lanolin, which is part of the cream, has high hygroscopicity and absorbs water, providing a cooling and softening effect on the skin. Creams are used for subacute and chronic inflammatory processes, as well as for dry skin or decreased elasticity. This dosage form resembles the hydrolipid mantle of the surface, it does not interfere with skin respiration and is well tolerated. That is why creams are used for daily "basic" skin care. Emulsions of the "oil in water" type are used to cleanse dry and sensitive skin (the so-called cosmetic "milk" or cosmetic "cream"). They are part of the classic multi-stage skin cleansing system used in beauty salons. In cosmetology, depending on the products included in the cream, there are cleansing, moisturizing, protective, and nourishing creams. When various acids are added to the rest of the creams (for example, hydroxy acids), peeling creams are produced for home peeling or pre-peeling preparation, and when a solid-phase filler is added (small particles of silicone, crushed fruit pits, etc.). Scrub creams for mechanical peeling (gommage).

An ointment is a medicinal form based on fats or fat-like substances: petroleum jelly, lanolin, animal fats, vegetable and mineral oils, hydrogenated oils, etc. Fatty indifferent bases fatten and soften dry, flaky skin, improve its elasticity, soften crusts and scales, and prevent moisture evaporation. Therefore, they increase inflammation, promote resolution of skin infiltration and penetration of pharmacological substances included in the base deep into the skin. In recent years, they have been successfully replaced by synthetic ointment bases: polyethylene glycols, cellulose derivatives, phospholipids, etc. They are well tolerated by the skin, easily penetrate it and are removed from the surface, do not oxidize or decompose. They do not fatten the skin, weakly prevent moisture evaporation, and are well emulsified. Traditional fatty ointment bases have a more pronounced occlusive effect than synthetic water-soluble ones. The effect of the dosage form on the skin is deeper, the more it delays the evaporation of moisture from its surface, therefore ointments are used in cases where it is necessary to achieve a deep and long-term effect of the drug on the affected area of the skin. The use of ointments is indicated for chronic inflammation of the skin, accompanied by stagnant hyperemia, peeling, infiltration and lichenification; for softening and removing crusts and thickened stratum corneum; in the treatment of superficial infectious and parasitic diseases of the skin. The ointment form is used in cosmetology for masks intended for dry and dehydrated skin.

Varnish is a volatile viscous liquid, which is a solution of film-forming substances in organic solvents (ethyl alcohol, acetone, ether, chloroform, dimethyl sulfoxide). It dries quickly and leaves a thin, transparent film with a pronounced adhesive property, which ensures long-term contact of the skin with the varnish introduced into the composition. A pharmacological agent, the physical action of the varnish is similar to the action of an ointment, so it is used for the purpose of deep exposure of potent pharmacological agents strictly to a limited area of the skin (with hyperkeratosis, vulgar warts, etc.). Due to the sealing and pressure exerted on the underlying skin, the varnish provides a deep effect, promoting the resorption of the infiltrate, accelerates the penetration of the pharmacological agents contained in it into the skin. The composition of the varnish includes medicinal substances of various actions: keratolytic, fungicidal, disinfectant, resolving, etc. Varnishes are also often used in foot cosmetology.

A plaster is a thick, viscous mass obtained by melting wax, rosin, resins, lanolin and other substances in different proportions. The composition includes a medicinal substance, the name of which determines the name of the plaster (salicylic, urea). The plaster acts similarly to varnish, but much deeper. It is prescribed when it is necessary to soften or loosen the thickened stratum corneum. The plaster has an irritating effect, so it is applied to small areas of the skin when inflammatory phenomena dry up. Just like varnish, it is used in foot cosmetology. In dermatosurgery, plasters with local anesthetics are used (for example, Emla),

Currently, ready-made external preparations are more often used in dermatocosmetology. They can be medical and cosmetic. The basic composition of any industrially manufactured external preparation is represented by the following components:

• active ingredient, or agent;
• base, or form;
• additional substances.

Active ingredients (agents) are introduced into external medicinal cosmetic forms in order to give them new properties and enhance their physical effect on the skin. It is customary to distinguish between pharmacological and cosmetic agents, although sometimes such a division is conditional. According to the predominant effect of pharmacological agents on the skin, the following groups are distinguished: anti-inflammatory, antipruritic, resolving, keratolytic, antimicrobial and antiseptic, fungicidal, antiviral, antiparasitic, cauterizing (destructive). It should be remembered that the same agent in different concentrations has a different, sometimes opposite effect on the skin (for example, ichthyol, various acids).

Anti-inflammatory agents include astringents, ichthyol and naphthalan in low concentrations, pimecrolimus, glucocorticosteroids. Astringents are used in the form of lotions and wet-drying dressings for acute inflammation with weeping (1-2% solutions of tannin and rhizorcinol, 0.25% solution of silver nitrate, 0.1% copper or zinc sulfate, aluminum acetate, etc.).

Ichthyol and naphthalan in concentrations up to 5% have a weak anti-inflammatory effect. They are used in the form of a solution (for example, 2% ichthyol) for the treatment of acute inflammatory processes and a paste (2-5% ichthyol or naphthalan) for the treatment of subacute inflammatory processes.

Pimecrolimus is a natural macrolide, one of the representatives of the ascomycin macrolactam class, related to non-steroidal selective anti-inflammatory drugs. The drug is available in the form of 1% cream (Elidel, Novartis). It suppresses the function of T-lymphocytes, the synthesis of interleukins and at the same time does not affect local and systemic immunological reactions, does not inhibit the growth of keratinocytes, fibroblasts and endothelial cells. In some cases, it can be considered as a replacement for topical steroids (for example, in atopic dermatitis, steroid dermatitis)

Glucocorticosteroids. Topical glucocorticosteroids have anti-inflammatory, antiallergic, epidermostatic, symptomatic (antipruritic, etc.) effects, and also inhibit collagen synthesis and slow down melanin synthesis in melanosomes. They are used in the form of cream, ointment, aerosol, solution.

According to their activity, glucocorticosteroids are divided into 4 groups:

• very strong acting ones - clobetasol propionate (Dermovate), etc.;
• strong acting - betamethasone (Kyterud), betamethasone valerate (Betnovate, Celestoderm B, Valoderm), betamethasone dipropionate (Beloderm), budesonide (Apulein), halomethasone monohydrate (Sicorten), hydrocortisone butyrate (Maticort, Mocoid), methylprednisolone aceponate (Advantai), mometasone furoate (Elocom), triamcinolone acetonide (Kenalog, Triacort, Cinacort, etc.), fluocinolone acetonide (Sinaflan, Ezocinop, Synoderm, Sinalar), fluticasone propionate (Cutivate), etc.;
• moderately active - prednicarbate (Dermatop), flumethasone pivalate (Locacorten, Lorindey, Fluvet), fluocortolone (Ultralan);
• weakly acting - hydrocortisone acetate (Hydrocortisone ointment), mazipredone hydrochloride (Depersolone), prednisolone (Prednisolone, Prednisolone ointment), etc.

Steroids should be used strictly according to indications. Indications for the use of topical steroids can be direct, or absolute, and indirect, or relative. Direct indications include simple and allergic dermatitis, indirect indications include chronic inflammatory dermatoses in the acute stage (atopic dermatitis, psoriasis, etc.). In cosmetology, steroids are also used to treat hypertrophic and keloid scars, less often as a bleaching agent, always in combination with topical retinoids, hydroquinone, and other drugs.

Contraindications for the prescription of topical steroids are infectious (primarily viral dermatoses, tuberculosis, syphilis, etc.) and parasitic (scabies, pediculosis) dermatoses. If it is necessary to suppress inflammation with signs of pyogenic or mycotic infection for the shortest possible time, combination drugs (Triderm, Pimafukort, Mikozolon, Dermozolone, etc.) can be prescribed.

It should be remembered that with prolonged and uncontrolled use of corticosteroids, especially those containing fluoride, a number of side effects develop: skin atrophy, telangiectasia, activation of infection (bacterial, fungal, viral), perioral (steroid) dermatitis, less often - striae, hypertrichosis. In this regard, it is recommended to follow the following rules:

• use topical corticosteroids with minimal frequency; do not prescribe the drug in doses exceeding 30 g per week for very strong and strong steroids, 50 g per week for moderately strong steroids, and 200 g per week for weak steroids, with a total duration of treatment exceeding 1 month;
• If possible, avoid applying topical corticosteroids to the skin of the face, genitals, palms and soles;
• Alternate areas of exposure when using highly active drugs.

Antipruritic agents include menthol (1% alcohol solution, ointment, talker), diphenhydramine (2-5% solution, talker, ointment), dimethindene (2% gel - Fenistil), dicaine and lidocaine (3% alcohol solution, ointment), anesthesin (10% alcohol solution, paste, ointment), salicylic acid (2% alcohol solution, ointment), phenol (0.5-3% alcohol solution, talker, ointment), vinegar (2-3% alcohol solution, talker), ethyl alcohol (10, 40, 70% aqueous solution).

The resolving agents include ichthyol (>5% ointment, cream, paste, per se), tar (3-20% ointment, cream, paste, perse), sulfur (5-20% ointment, cream), ASD-3 fraction (3-10% ointment, cream, paste), anthralin (0.25, 1, 3% ointment - Dithranol).

Keratolytic agents include salicylic acid (5-15%), lactic acid (5-15%), resorcinol (5-15%), urea (>10%), hydroxy acids (25-70%). In cosmetology, they are used for chemical peeling.

The group of antimicrobial and antiseptic agents includes chlorhexidine bigluconate (0.05% aqueous solution), miramistin (0.01% aqueous solution), dioxidine (0.5-1% aqueous solution, 5% ointment), various dyes (furacilin, ethacridine lactate, brilliant green, iodine, etc.), fusidic acid (Fucidin), antibiotics, sulfanilamide drugs (streptocide - 5-10% powder, ointment; silver sulfadiazine - 1% ointment, Dermazin cream; mafenide - 10% ointment), bismuth salts (dermatol, xeroform - 3-10% powder, paste), mercury salts (mercuric aminochloride and mercury dichloride - rarely used now). In dermatology, the following antibacterial drugs are most frequently used: bacitracin, heliomycin (Bapeocin), gentamicin (Garamycin), clindamycin (Dalocin 7), mupirocin (Bactroban), erythromycin (Zipnerit).

Fungicidal agents are represented by azoles (bifoiazole - Mikospot isoconazole - Travogen, ketoconazole - Nizoral, clotrimazole ~ Clotrimazole, Canesten, Candid, etc., econazole - Ecolin, etc.), terbinafines (naftifine - Exoderil, terbinafine - Lamisil, Terbizil, etc.), ciclopirox derivatives (ciclopiroxolamine - Batrafen), amorolfine (Loceryl). Iodine, sulfur, tar, undecylenic acid (Mikoseptin) also have an antifungal effect. Anticandidal agents include polyene antibiotics (for example, natamycin - Pimafucin).

Antiviral agents include acyclovir (Zovirax, Acyclovir, tromantadine (Viru-Merz), epervudine (Gevizon), glycyrrhizic acid (Epigen)

Antiparasitic agents include benzyl benzoate (10-20% ointment, suspension), sulfur (10-20% ointment, chatterbox), liidan (1% lotion, cream, ointment), crotamiton (10% lotion, cream, ointment), permethrin (0.5-1% cream, alcohol solution), tar (5-20% ointment, alcohol solution).

Cauterizing (destructive) agents: 10-50% silver nitrate (lapis), 30% resorcinol, undiluted phenol, undiluted trichloroacetic acid, 10-20% podophyllin, 0.5% podophyllotoxin.

Additional substances included in external pharmacological and cosmetic preparations include: aromatic fragrances, dyes, preservatives. The modern trend in the production of external preparations is to reduce the amount of additional substances, especially those that can act as allergens (haptens). It is believed that hypoallergenic drugs and cosmetics contain a minimum of additional substances. In recent years, many companies have included tested compounds of plant origin as additional substances, replacing synthetic ones with them.

Any cosmetic or medical product may contain various microorganisms (bacteria, fungi) that enter it from raw materials or during the production process and packaging. Many European countries and America have standards regulating the amount of certain microorganisms in a product. In order to solve this problem, manufacturers carefully process raw materials, automate the production process as much as possible and include preservatives in the composition of the products. Unfortunately, the latter is a "necessary evil": it is much better to add a preservative and achieve compliance with established safety and quality standards than to release contaminated products. It is also extremely important to store the product correctly after its release (avoid exposure to direct sunlight, high ambient temperatures). It is known that bacteria and fungi tend to multiply in the aqueous phase of cosmetic products, therefore, those with a high water content pose the greatest risk of contamination with microorganisms. The most commonly used preservatives are: benzoic acid, benzyl alcohol, formaldehyde, various parabens (melhylparaben), urea derivatives (irnidazolidmyl urea), Quatemium 15.

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General information about skin permeability

In terms of permeability, the skin is an integumentary organ consisting of three anatomically distinct layers: the stratum corneum (about 10 μm thick), the epidermis (about 100 μm thick), and the papillary dermis (about 100-200 μm thick). Each of these layers has different diffusion indices. Even the skin of a completely healthy individual allows the penetration of virtually any substance, and the penetration rate of various agents can vary significantly. In particular, human skin is weakly resistant to water, and at the same time it is virtually impermeable to sodium, potassium, and other ions in an aqueous solution. Most covalent substances such as glucose, urea, and macromolecules have low permeability constants. On the contrary, a number of aliphatic alcohols, as well as various substances dissolved in organic solvents (e.g., alcohol, ether, etc.), have high permeability parameters.

The degree of transcutaneous absorption also depends on the anatomical localization. Thus, the permeability of the skin in the facial area, especially the forehead, the back of the hands, and the scrotum is significantly higher than that of the skin of the trunk, upper and lower extremities. It is also known that the palms and soles are impermeable to almost all molecules, with the exception of the water molecule. Age also plays a significant role: in childhood and old age, the permeability of the skin is significantly higher than in adolescence and middle age.