Keratolytics

Medicated Dandruff Shampoos. Dandmff is a scalp condition characterized by the production of excessive cellular material (18). A number of shampoos have been marketed which are designed to control and alleviate this condition, and many additives have been included in shampoo compositions to classify them as treatment products for dandmff. These additives include antimicrobial additives, eg, quaternary ammonium salts keratolytic agents, eg, saUcychc acid and sulfur heavy metals, eg, cadmium sulfide coal tar resorcinol and many others. More recent (ca 1993) systems use selenium sulfide [7488-56-4] or zinc pyrithione [13463-41 -7] as active antidandmff shampoo additives. Both of these additives are classified as dmgs, but can be found in over-the-counter products. A stronger version, incorporating the use of higher levels of selenium sulfide in a shampoo, is available but requires a prescription for purchase. 

Sahcyhc acid USP, EP, and other pharmacopeia grades are used medically as antiseptic, disinfectant, antifungal, and keratolytic agents. Sahcyhc acid is formulated in lotion or ointment formulations for the treatment of dandmff, eczema, psoriasis, and various parasitic skin diseases. Because the keratolytic property of this aromatic acid has use in the safe removal of dead skin cells from the surface of healthy skin, the acid is used in concentrated sahcyhc acid solutions or suspensions to remove warts and corns. In more dilute form, sahcyhc acid preparations have found use in dandmff and eczema treatment. Sahcyhc acid has been considered and found effective by the Advisory Committees to the FDA in various over-the-counter (OTC) dmg regulated uses. Among these are acne products, dermatitis, dry skin, dandmff and psoriasis products, and foot care products (24). 

Older Compounds. Some antimycotics have been used for a long time Whitfield s ointment is a typical example (1907). The ointment usually contains 6% ben2oic acid [65-85-0] and 3% sahcyhc acid [69-72-7] C H O. The action is attributed to the keratolytic effect of the sahcyhc acid... 

Other drugs are a combination of a keratolytic agent (mesulfen [135-58-0] C24H22S2) and the well-known antimycotic 2inc undecylenate [557-08-4] ... 

The keratolytic analogue motretinide (53) is effective in treating acne and the excess epithelial growth characteristic... 

The keratolytics are contraindicated in patients with known hypersensitivity to the drugs and for use on moles, birthmarks, or warts with hair growing from them, on genital or facial warts, on warts on mucous membranes, or on infected skin. Prolonged use of the keratolytics in infants or patients with diabetes or impaired circulation is contraindicated. Salicylic acid... 

A keratolytic agent would be safe to use on which of the following skin conditions ... 

Salicylic acid is used to treat acne, warts, dandruff, psoriasis, and similar conditions. In the treatment of acne, it slows the shedding of skin cells in hair follicles, so they do not clog the pores and cause pimples. It also has a keratolytic effect—it causes dead skin cells to slough off— which removes the top layer of skin and clears existing pore clogs. 

Huber C, Christophers E (1977) Keratolytic elfect of salicylic acid. Arch Dermatol Res 257 293-297... 

Converts physiologically into lactic acid Soluble in water and alcohol Keratolytic action Desmoplastic property... 

Soluble in water, ether and alcohol Bactericidal agent Reducing agent Keratolytic properties... 

P.G. Unna, a German dermatologist, was the first to describe the properties and use of salicylic acid. It has since been used for many decades as a keratolytic agent in concentrations of 3 to 6%. Salicylic acid is frequently utilized in topical acne preparations because of its comed-olytic effects. In addition, it facilitates the penetration of other topical agents. 

Salicylic acid (ortho hydroxybenzoic add) is a beta hydroxy acid agent. It is a lipophilic compound which produces desquamation of the stratum corneum via removal of intercellular lipids [3] (see salicylic acid section). Given its keratolytic effects, it has become an increasingly popular superficial peeling agent. Salicylic acid peels induce injury via thinning or removal of the stratum corneum. In addition, salicylic acid potentially enhances the penetration of TCA. 

Salicylic acid has a keratolytic effect, thus eliminating superficial pigmented keratinocytes and stimulating cells turnover. This superficial peeling allows TCA to act a low concentration to remove pigmented keratinocytes through papillary dermis (see Fig. 14.12). 

Keratolytic agents such as salicylic acid are often added to bath oil or shampoos (typically 3% to 4%) for scalp psoriasis.10 Salicylic acid can also be added to topical corticosteroid preparations to enhance steroid penetration (salicylic acid breaks down keratin). 

Coal tar is keratolytic and may have anti-proliferative and anti-inflammatory effects.2 Coal tar products include crude coal tar and tar distillates (liquor carbonis detergens) available as ointments, creams, and shampoos in various strengths. Preparations containing coal tar may precipitate folliculitis,10 will stain clothing, and have an unpleasant odor. They are also photosensitizing and can be combined with UVB phototherapy (Goekermann s regimen) to increase treatment response.19,20... 

It is used in the treatment of mild to moderate acne vulgaris and has comedolytic, keratolytic, and antiinflammatory action. 

Salicylic acid, sulfur, and resorcinol are second-line topical therapies. They are keratolytic and mildly antibacterial agents. Salicylic acid has comedolytic and antiinflammatory action. 

---