title: Cell-based in vitro models for predicting drug permeability.
abstract: BACKGROUND
  In vitro cell models have been used to predict drug permeation in early stages of drug development, since they represent an easy and reproducible method, allowing the tracking of drug absorption rate and mechanism, with an advantageous cost-benefit ratio. Such cell-based models are mainly composed of immortalized cells with an intrinsic ability to grow in a monolayer when seeded in permeable supports, maintaining their physiologic characteristics regarding epithelium cell physiology and functionality.
  
  
  METHODS
  This review summarizes the most important intestinal, pulmonary, nasal, vaginal, rectal, ocular and skin cell-based in vitro models for predicting the permeability of drugs. Moreover, the similitude between in vitro cell models and in vivo conditions are discussed, providing evidence that each model may provisionally resemble different drug absorption route.
  
  
  CONCLUSIONS
  Despite the widespread use of in vitro cell models for drug permeability and absorption evaluation purposes, a detailed study on the properties of these models and their in vitro-in vivo correlation compared with human data are required to further use in order to consider a future drug discovery optimization and clinical development.
authors.affiliation: Department of Pharmaceutical Technology, LTF/CICF, Faculty of Pharmacy, University of Porto, Portugal. bruno.sarmento@ff.up.pt
authors.forename: Bruno
authors.initials: B
authors.lastname: Sarmento
authors.forename: Fernanda
authors.initials: F
authors.lastname: Andrade
authors.forename: Sara Baptista
authors.initials: SB
authors.lastname: da Silva
authors.forename: Francisca
authors.initials: F
authors.lastname: Rodrigues
authors.forename: José
authors.initials: J
authors.lastname: das Neves
authors.forename: Domingos
authors.initials: D
authors.lastname: Ferreira
mesh_terms: D000818:Animals; D018938:Caco-2 Cells; D002460:Cell Line; D002463:Cell Membrane Permeability / Q000187:drug effects*; D005123:Eye / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007408:Intestinal Absorption / Q000187:drug effects; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000166:cytology / Q000187:drug effects; D008168:Lung / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D008954:Models, Biological; D010539:Permeability; D004364:Pharmaceutical Preparations / Q000378:metabolism*; D012867:Skin / Q000166:cytology / Q000187:drug effects / Q000378:metabolism
chemical_list: D004364:Pharmaceutical Preparations