title: Cutaneous bioassay of salicylic acid as a keratolytic.
abstract: Keratolytic efficacy of topical preparations containing salicylic acid was studied in humans utilizing adhesive tape stripping and quantifying SC removal by protein analysis. In combination with tape stripping, squamometry was used to evaluate the influence of salicylic acid on skin surface scaliness and desquamation. Furthermore, skin barrier perturbation and skin irritancy was recorded and related to the dermatopharmacological effect of the preparations. In contrast to squamometry, tape stripping combined with protein analysis was sensitive in detecting keratolytic effect of salicylic acid within hours of application. Importantly, whereas the pH of the preparations only minimally influenced efficacy, local dermatotoxicity was significantly increased at acidic pH. This indicates that the quest to increase the amount of free, non-dissociated SA is, in fact, counterproductive as the more acidic preparations resulted in skin irritation and barrier disruption.
authors.affiliation: Department of Dermatology, University of California, 90 Medical Center Way, Surge Building #110, P.O. Box 0989, San Francisco, CA 94143-0989, USA.
authors.forename: S J
authors.initials: SJ
authors.lastname: Bashir
authors.forename: F
authors.initials: F
authors.lastname: Dreher
authors.forename: A L
authors.initials: AL
authors.lastname: Chew
authors.forename: H
authors.initials: H
authors.lastname: Zhai
authors.forename: C
authors.initials: C
authors.lastname: Levin
authors.forename: R
authors.initials: R
authors.lastname: Stern
authors.forename: H I
authors.initials: HI
authors.lastname: Maibach
mesh_terms: D000279:Administration, Cutaneous; D000328:Adult; D003880:Dermatology / Q000379:methods / Q000639:trends; D004341:Drug Evaluation / Q000379:methods*; D004890:Erythema / Q000139:chemically induced; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007641:Keratolytic Agents / Q000008:administration & dosage / Q000737:chemistry / Q000627:therapeutic use*; D008297:Male; D008610:Menthol / Q000008:administration & dosage / Q000009:adverse effects; D020156:Salicylic Acid / Q000008:administration & dosage / Q000009:adverse effects*; D023422:Skin Irritancy Tests / Q000379:methods; D012879:Skin Physiological Phenomena / Q000187:drug effects; D012996:Solutions / Q000008:administration & dosage / Q000009:adverse effects / Q000737:chemistry; D013997:Time Factors; D014870:Water Loss, Insensible / Q000187:drug effects / Q000502:physiology
chemical_list: D007641:Keratolytic Agents; D012996:Solutions; D008610:Menthol; D020156:Salicylic Acid