title: Modelling dermal drug distribution after topical application in human.
abstract: OBJECTIVE
  To model and interpret drug distribution in the dermis and underlying tissues after topical application which is relevant to the treatment of local conditions.
  
  
  METHODS
  We created a new physiological pharmacokinetic model to describe the effect of blood flow, blood protein binding and dermal binding on the rate and depth of penetration of topical drugs into the underlying skin. We used this model to interpret literature in vivo human biopsy data on dermal drug concentration at various depths in the dermis after topical application of six substances. This interpretation was facilitated by our in vitro human dermal penetration studies in which dermal diffusion coefficient and binding were estimated.
  
  
  RESULTS
  The model shows that dermal diffusion alone cannot explain the in vivo data, and blood and/or lymphatic transport to deep tissues must be present for almost all of the drugs tested.
  
  
  CONCLUSIONS
  Topical drug delivery systems for deeper tissue delivery should recognise that blood/lymphatic transport may dominate over dermal diffusion for certain compounds.
authors.affiliation: School of Biomolecular and Physical Sciences, Griffith University, Gold Coast, Queensland 4222, Australia. Y.Anissimov@Griffith.edu.au
authors.forename: Yuri G
authors.initials: YG
authors.lastname: Anissimov
authors.forename: Michael Stephen
authors.initials: MS
authors.lastname: Roberts
mesh_terms: D000287:Administration, Topical; D001692:Biological Transport; D002851:Chromatography, High Pressure Liquid; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008657:Metabolic Clearance Rate; D008954:Models, Biological; D008970:Molecular Weight; D004364:Pharmaceutical Preparations / Q000008:administration & dosage* / Q000097:blood / Q000737:chemistry; D010599:Pharmacokinetics; D012867:Skin / Q000378:metabolism*; D012869:Skin Absorption; D012995:Solubility; D012996:Solutions; D014018:Tissue Distribution
chemical_list: D004364:Pharmaceutical Preparations; D012996:Solutions