Absorption, distribution, metabolism drug delivery systems

Scheme 2 Pharmaceutical nanotechnology s main areas of focus, namely, the manipulation and processing the physicochemical characterization of a variety of systems in relation to then-application their biological evaluation. The last involves an understanding of the interaction between their physicochemical properties and biological barriers and environments. Absorption, distribution, metabolism, and toxicology refer to both the drug once released from the delivery system and the delivery system itself, while being aware of possible synergistic effects of the two.

These new drug delivery systems will permit the consideration of drug candidates that would not have been developed with yesterday s technology and knowledge of drug absorption, distribution, metabolism, and excretion. 

Factors analogous to those affecting gut absorption also can affect drug distribution and excretion. Any transporters or metabolizing enzymes can be taxed to capacity—which clearly would make the kinetic process nonlinear (see Linear versus Nonlinear Pharmacokinetics ). In order to have linear pharmacokinetics, all components (distribution, metabolism, filtration, active secretion, and active reabsorption) must be reasonably approximated by first-order kinetics for the valid design of controlled release delivery systems. 

---