Salicylic Acid Gel

Rx Only

FOR TOPICAL USE ONLY. NOT FOR OPHTHALMIC, ORAL OR INTRAVAGINAL USE.

Salicylic Acid 6% Gel is applied topically and used in the removal of excessive keratin in hyperkeratotic skin disorders. Each gram of Salicylic Acid 6% Gel contains salicylic acid 6% as the active ingredient, and the following inactive ingredients: propylene glycol, SD-40 alcohol (21%), hydroxypropylcellulose and purified water.

Salicylic acid has been shown to produce desquamation of the horny layer of skin while not affecting qualitative or quantitative changes in structure of the viable epidermis.1,2 The mechanism of action has been attributed to dissolution of intercellular cement substance.3 In a study of the percutaneous absorption of salicylic acid from Salicylic Acid 6% Gel in four patients with extensive active psoriasis, Taylor and Halprin4 showed that peak serum salicylate levels never exceeded 5 mg/100 mL even though more than 60% of the applied salicylic acid was absorbed. Systemic toxic reactions are usually associated with much higher serum levels (30 to 40 mg/100mL). Peak serum levels occurred within 5 hours of the topical application under occlusion. The sites were occluded for 10 hours over the entire body surface below the neck. Since salicylates are distributed in the extracellular space, patients with a contracted extracellular space due to dehydration or diuretics have higher salicylate levels than those with a normal extracellular space.5 (See PRECAUTIONS).

The major metabolites identified in the urine after topical administration are salicyluric acid (52%), salicylate glucuronides (42%), and free salicylic acid (6%).4 The urinary metabolites after percutaneous absorption differ from those after oral salicylate administration; those derived from percutaneous absorption contain more glucuronides and less salicyluric and salicylic acid. Almost 95% of a single dose of salicylate is excreted within 24 hours of its entrance into the extracellular space.5

Fifty to eighty percent of salicylate is protein bound to albumin. Salicylates compete with the binding of several drugs and can modify the action of these drugs. By similar competetive mechanisms other drugs can influence the serum levels of salicylate. (See PRECAUTIONS).

For the removal of excess keratin in hyperkeratotic disorders, including scaling associated with psoriasis or thickened skin of palms and soles, corns and calluses.

Excessive erythema and scaling conceivably could result from use on open skin lesions.

See WARNINGS