title: An evaluation of the latest in vitro tools for drug metabolism studies.
abstract: BACKGROUND
  Drugs are indispensable for human welfare nevertheless there is a lack of safe drugs. Obtaining pharmacokinetics information, especially metabolism, is a requirement during preclinical and clinical drug development so that in vitro tools represent a simple path where it is possible to assess drug toxicity and predict drug safety in humans.
  
  
  METHODS
  This review covers the latest in vitro tools developed for assessing drug toxicity in different organs. A special focus is given to hepatic models, as it is the main organ responsible for drug metabolism and consequently bioactivation and detoxification reactions. Three-dimensional culture models have been widely developed, resembling in vivo-like conditions, and are also discussed in this review.
  
  
  CONCLUSIONS
  Several in vitro tools to assess hepatic drug metabolism have been developed, however, novel in vitro methods to investigate extra-hepatic drug metabolism still need to be improved. These methods are able to reduce the number of animal used in preclinical experiments, but in vivo tests are mandatory for drug approval and commercialization.
authors.affiliation: IINFACTS - Instituto de Investigaçãoe Formação Avançada em Ciênciase Tecnologias da Saude, Instituto Superior de Ciências da Saude-Norte, Department of Pharmaceutical Sciences , CESPU, Gandra-PRD , Portugal +351 22 415 71 89 ; Bruno.Sarmento@ineb.up.pt.
authors.forename: Ana
authors.initials: A
authors.lastname: Costa
authors.forename: Bruno
authors.initials: B
authors.lastname: Sarmento
authors.forename: Vítor
authors.initials: V
authors.lastname: Seabra
mesh_terms: D000818:Animals; D002460:Cell Line; D064420:Drug-Related Side Effects and Adverse Reactions; D022781:Hepatocytes / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D008658:Inactivation, Metabolic; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000187:drug effects; D007668:Kidney / Q000187:drug effects / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008168:Lung / Q000187:drug effects / Q000378:metabolism; D008962:Models, Theoretical