title: Impacts of chemical enhancers on skin permeation and deposition of terbinafine.
abstract: OBJECTIVE
  The addition of chemical enhancers into formulations is the most commonly employed approach to overcome the skin barrier. The objective of this work was to evaluate the effect of vehicle and chemical enhancers on the skin permeation and accumulation of terbinafine, an allylamine antifungal drug.
  
  
  METHODS
  Terbinafine (1% w/w) was formulated as a Carbopol 934 P gel formulation in presence and absence of three chemical enhancers, nerolidol, dl-limonene and urea. Terbinafine distribution and deposition in stratum corneum (SC) and skin following 8-h ex vivo permeation study was determined using a sequential tape stripping procedure. The conformational order of SC lipids was investigated by ATR-FTIR spectroscopy.
  
  
  CONCLUSIONS
  Nerolidol containing gel formulation produced significantly higher enhancement in terbinafine permeation through skin and its skin accumulation was increased. ATR-FTIR results showed enhancer induced lipid bilayer disruption in SC. Urea resulted in enhanced permeation of terbinafine across the skin and a balanced distribution to the SC was achieved. But, dl-limonene could not minimize the accumulation of terbinafine in the upper SC.
  
  
  CONCLUSIONS
  Nerolidol dramatically improved the skin permeation and deposition of terbinafine in the skin that might help to optimize targeting of the drug to the epidermal sites as required for both of superficial and deep cutaneous fungal infections.
authors.affiliation: Department of Pharmaceutical Technology, Faculty of Pharmacy, Istanbul University, 34116 Beyazıt , Istanbul , Turkey and.
authors.forename: Meryem Sedef
authors.initials: MS
authors.lastname: Erdal
authors.forename: Ayca Yıldız
authors.initials: AY
authors.lastname: Peköz
authors.forename: Buket
authors.initials: B
authors.lastname: Aksu
authors.forename: Ahmet
authors.initials: A
authors.lastname: Araman
mesh_terms: D000279:Administration, Cutaneous; D000818:Animals; D000935:Antifungal Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics; D053138:Cyclohexenes / Q000494:pharmacology; D000077222:Limonene; D009281:Naphthalenes / Q000008:administration & dosage* / Q000493:pharmacokinetics; D010539:Permeability / Q000187:drug effects; D014677:Pharmaceutical Vehicles / Q000494:pharmacology*; D012717:Sesquiterpenes / Q000494:pharmacology; D012867:Skin / Q000187:drug effects* / Q000378:metabolism*; D012869:Skin Absorption / Q000187:drug effects*; D013552:Swine; D000077291:Terbinafine; D013729:Terpenes / Q000494:pharmacology; D014508:Urea / Q000494:pharmacology
chemical_list: D000935:Antifungal Agents; D053138:Cyclohexenes; D009281:Naphthalenes; D014677:Pharmaceutical Vehicles; D012717:Sesquiterpenes; D013729:Terpenes; D014508:Urea; D000077222:Limonene; D000077291:Terbinafine; C037055:nerolidol