title: Liquid-crystalline membrane permeation ability for selected nitro hair dyes.
abstract: OBJECTIVE
  A comparison of permeation ability of selected semi-permanent hair dyes and an attempt to estimate the influence of fundamental physicochemical parameters on dyes' epidermal penetration rate.
  
  
  METHODS
  Dyes' permeation ability through liposome membrane (as a model of stratum corneum) with side-by-side cells was assessed.
  
  
  RESULTS
  It has been shown that the chosen dyes are capable of permeating the membrane. High penetration coefficients (Kp) were obtained for a simple nitrophenylenediamines and nitroaminophenols. Their N-, O-hydroxyalkyl substitution significantly limits penetration. H-bonding capability has a major impact on the investigated dyes' permeation ability. Substituents with H-bonding properties can significantly limit dyes' penetration, even in the case of lipophilic structures. Special attention should be placed into compounds with strong intramolecular H-bonding properties, which improve transmembrane transport.
  
  
  CONCLUSIONS
  Substitution patterns have an influence on selected nitro dyes' permeation through a model stratum corneum. Permeation is limited by dyes diffusive properties (mostly by its H-bonding properties). Hydroxyalkylation results in hindered dyes permeation: purple, violet and blue nitrophenylenediamine or nitroaminophenol derivatives are less permeable than its not substituted analogues.
authors.affiliation: Academy of Cosmetics and Health Care, Warsaw, Poland. i.bialas@wszkipz.pl
authors.forename: Iwona
authors.initials: I
authors.lastname: Bialas
authors.forename: Jacek
authors.initials: J
authors.lastname: Arct
authors.forename: Miroslaw
authors.initials: M
authors.lastname: Mojski
authors.forename: Stanislaw
authors.initials: S
authors.lastname: Krus
mesh_terms: D040761:Biomimetic Materials / Q000737:chemistry*; D004058:Diffusion; D006202:Hair Dyes / Q000737:chemistry*; D006801:Humans; D008081:Liposomes / Q000737:chemistry*; D050866:Liquid Crystals / Q000737:chemistry*; D008422:Materials Testing; D008567:Membranes, Artificial; D010539:Permeability; D012867:Skin / Q000737:chemistry*
chemical_list: D006202:Hair Dyes; D008081:Liposomes; D008567:Membranes, Artificial