ABSTRACT
The preclinical pharmacokinetics and pharmacodynamics of drug formulations are
traditionally evaluated in animal models with invasive surgical methods. A large number
of experimental animals are sacrificed during the process of preclinical development. The
results obtained in the preclinical studies with these invasive methods are often not
predictive of the outcome of later clinical studies. Options are very limited for clinical
evaluation of the pharmacokinetics and pharmacodynamics of new formulations. The
studies with surgery-or biopsy-based tissue sampling often do not accurately reflect the
true systemic efficacy of the drug formulations. Many drug compounds have failed to
acquire the Food and Drug Administration (FDA) approval for clinical applications after
expensive preclinical and clinical studies.
