Products that reduce pigmentation (bleaching agents)

Pigmentation-reducing or bleaching agents are widely used for hyperpigmentation of various origins: melasma (chloasma), lentigo, freckles, post-inflammatory pigmentation and other conditions.

The ideal bleaching agent and preparation should have fairly pronounced depigmenting properties and at the same time not cause side effects. Currently existing potent bleaching agents cause a number of side effects, which should always be remembered by the specialist.

Whitening agents include the following agents: hydroquinone and its derivatives, topical retinoids, azelaic acid, benzoyl peroxide, topical glucocorticoids, ascorbic acid, hydroxy acids and other drugs.

Hydroquinone and its derivatives (monobenzyl ether of hydroquinone, etc.) are the most powerful bleaching agents. The bleaching effect is associated with slowing down the formation of melanosomes, accelerating their degradation processes, slowing down the synthesis of RNA and DNA in melanocytes. In a number of European countries, a 2-5 (10%) solution or emulsion (cream) of hydroquinone is used. Prescribed once a day, at night, for a period of 5-7 weeks. Combination drugs including hydroquinone and topical retinoids, corticosteroids, and various acids are quite popular. Side effects include a high incidence of allergic dermatitis, irritant action (simple dermatitis), hyperpigmentation, and confetti-like leukoderma. It is emphasized that monobenzyl ether of hydroquinone more often causes side effects than hydroquinone. Due to the high incidence of side effects, they are not currently used in our country.

Topical retinoids reduce pigmentation by influencing the melanogenesis process in melanosomes, on the one hand, and accelerating the rate of epithelial layer renewal, on the other. Traditionally, retinoids are used for external acne therapy. Tretinoin and isotretinoin (0.025-0.1%) were previously used for whitening purposes; currently, 0.1% adapalene (Differin, gel, cream) can be used. Topical retinoids are prescribed once a day, at night, for a long time (up to six months). Currently, retinoids are included in masks and peeling products (for example, "yellow peeling"). Side effects of retinoids include their irritating effect.

Azelaic acid is also an external preparation for the treatment of acne. The depigmenting effect is associated with a decrease in the activity of the enzyme tyrosinase and the ability to slow the proliferation of pathologically altered melanocytes. It is prescribed in the form of a 20% cream (Skinoren, cream) 1-2 times a day, for a long time (at least six months). Azelaic acid is generally well tolerated, and can rarely have a slight irritating effect.

Benzoyl peroxide is also used for external treatment of acne, especially pustular acne. The whitening effect is due to the fact that benzoyl peroxide discolors melanin by oxidizing it, and also has an exfoliating effect. 2.5-10% benzoyl peroxide is used in the form of a gel, emulsion, solution (for example, Baziron AC, 5% gel). Side effects may include simple dermatitis, and allergic dermatitis is extremely rare.

Topical glucocorticoids have a whitening effect by slowing down the processes of melanin synthesis in melanosomes and reducing the inflammatory reaction. They are used extremely rarely, only in combination with topical retinoids, hydroquinone and other whitening agents. It is not recommended to use fluorinated glucocorticosteroids, as well as any drugs from this group on the skin of the face. Side effects include skin atrophy, activation of bacterial, mycotic and viral infections, development of steroid (perioral) dermatitis.

Ascorbic acid not only suppresses melanin production at various stages of melanogenesis, but also promotes the transformation of eumelanin into leukomelanin. It is prescribed in a concentration of up to 10%, 1-2 times a day, for a long time (at least six months), sometimes in combination with other agents. It is included in some professional peels.

Hydroxy acids (alpha, beta, polyhydroxy acids) are widely used in cosmetology for peeling, one of the purposes of which is to reduce unwanted pigmentation. The whitening effect is mainly associated with a decrease in tyrosinase activity and acceleration of epithelial layer change. Most hydroxy acids are of natural origin. The most commonly prescribed are glycolic, lactic, malic, malic, salicylic and other acids. The concentration and pH depend on the desired depth of peeling effect.

New compounds for reducing pigmentation are constantly appearing on the cosmetic market. In particular, 4l-butyl-resorcinol (Rutsinol) not only inhibits tyrosinase, but also suppresses the activity of the enzyme TRPI, which is involved in the synthesis of eumelanin. Rutsinol is part of the serum and cream Iklen (MERC Medication Familiar, France). In recent years, a derivative of licorice - glabridin - has come to be used. This substance is included in various whitening ranges, as well as for preventive purposes in sunscreens (Bioderma brand). Currently, the old, previously very popular method of skin whitening with the help of preparations containing white precipitate mercury is practically not used due to the high risk of developing allergic dermatitis. It should also be emphasized the need for effective photoprotection against the background of the treatment of hyperpigmentation of any genesis.

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