Pharmacotherapeutic group: Analgesic (Topical).
Pharmacology: METHYL SALICYLATE: Methyl salicylate is extensively metabolized to salicylic acid in the dermal and subcutaneous tissues following topical administration.
Results from another study demonstrating high tissue to plasma ratios following topical application of Methyl salicylate formulation suggest that direct penetration and not recirculation in the blood is responsible for the salicylate concentrations found.
Methyl salicylate may be absorbed through intact skin. Percutaneous absorption is enhanced by exercise, heat, occlusion, or disruption of the integrity of the skin. The amount absorbed will also be increased by application to large areas of skin. Results from a study in healthy subjects demonstrated that a considerable amount of salicylic acid may be absorbed through the skin after topical application of products containing Methyl salicylate.
MENTHOL: When applied to the skin it dilates the blood vessels, causing a sensation of coldness followed by an analgesic effect.
After absorption, Menthol is excreted in the urine and bile as a glucuronide.
CAMPHOR: Camphor is readily absorbed from all administration sites. It is hydroxylated in the liver to yield hydroxycamphor metabolites which are then conjugated with glucuronic acid and excreted in the urine.
Camphor crosses the placenta.