Category: topical
Aliases: BHA, 2-hydroxybenzoic acid
Lipophilic β-hydroxy acid — partitions preferentially into sebaceous follicles where it dissolves the lipid matrix between corneocytes, releasing comedonal contents. This follicle-penetrating property is why it is more effective than AHAs for comedonal acne despite lower overall exfoliant strength. Also has modest anti-inflammatory activity (structurally related to aspirin; inhibits prostaglandin synthesis at the local concentrations achieved in the epidermis). Systemic absorption ~10–25% of applied dose (formulation- and surface-area-dependent per Schwarb 1999); salicylate toxicity is a concern only with very large body-surface application in children or patients with impaired barrier.
TD: 3h