The problem of transposing in vitro results is particularly acute in areas such as toxicology where animal experiments are being phased out and are increasingly being replaced by alternative tests.
Two solutions are now commonly accepted: The two approaches can be applied simultaneously allowing in vitro systems to provide adequate data for the development of mathematical models.
To comply with push for the development of alternative testing methods, increasingly sophisticated in vitro experiments are now collecting numerous, complex, and challenging data that can be integrated into mathematical models.
IVIVE in pharmacology can be used to assess pharmacokinetics (PK) or pharmacodynamics (PD)..[citation needed] Since biological perturbation depends on concentration of the toxicant as well as exposure duration of a candidate drug (parent molecule or metabolites) at that target site, in vivo tissue and organ effects can either be completely different or similar to those observed in vitro.
It is generally accepted that physiologically based PK (PBPK) models, including absorption, distribution, metabolism, and excretion of any given chemical are central to in vitro - in vivo extrapolations.