title: Skin disposition of menthol after its application in the presence of drug substances.
abstract: Many drug products that are applied onto the skin contain menthol. Menthol plays a dual role in the analgesic and anti-inflammatory drugs: it causes cooling and local anesthetic effects and, being a penetration enhancer, it increases the skin permeation of the drug substances. However, there are no data concerning the skin penetration of menthol after its application in the most commonly used vehicles and in the presence of drug substances. Therefore, this study evaluated the ex vivo skin disposition of menthol after application of the commercially available drug products containing aluminum acetotartrate, methyl salicylate, ibuprofen and naproxen, using full human-skin mounted in flow-through diffusion cells. After 15, 30 and 60 min of application, the skin was progressively tape-stripped into three fractions of stratum corneum and the remaining epidermis with dermis. The content of menthol in the skin layers was determined by GC method. Varying degrees of penetration of menthol into the skin layers was observed, depending on its amount in the vehicle and the presence of drug substance. In the presence of aluminum acetotartrate, the skin penetration of menthol was limited only to the outer fraction of the stratum corneum. In the case of drug products containing naproxen, the concentration of the drug substance significantly influenced the skin penetration of menthol.
authors.affiliation: Department of Pharmaceutical Technology, Medical University of Gdansk, Gdansk, Poland. kcal@wp.pl
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Cal
mesh_terms: D000328:Adult; D004817:Epidermis / Q000378:metabolism; D005260:Female; D006801:Humans; D007052:Ibuprofen / Q000008:administration & dosage; D008610:Menthol / Q000008:administration & dosage / Q000493:pharmacokinetics*; D008875:Middle Aged; D009288:Naproxen / Q000008:administration & dosage; D012459:Salicylates / Q000008:administration & dosage; D012867:Skin / Q000378:metabolism*; D013644:Tartrates / Q000008:administration & dosage
chemical_list: D012459:Salicylates; D013644:Tartrates; C041214:acetotartaric acid; D008610:Menthol; D009288:Naproxen; C033069:methyl salicylate; D007052:Ibuprofen