The importance of studying oral drug absorption is well recognized by both researchfacilities/institutions and the pharmaceutical industry. The use of mathematical models canrepresent a very profitable and indispensable tool to understand oral drug absorption. Indeed,mathematical models can verify the correctness of the mechanisms proposed to describe drugrelease, absorption, distribution and elimination thus reducing the number of expensive andtime-consuming experiments. In this paper we develop a mathematical approach able to modelboth the polymeric particle mediated delivery and the gastrointestinal absorption-metabolismexcretion(ADME) of a given drug. As a model drug a poorly water-soluble drug (vinpocetine)in both the amorphous and nanocrystalline state is considered. The delivery system is obtainedby drug cogrinding with a polymer (cross-linked polyvinilpyrrolidone). As the proposedmathematical model can properly fit the in vivo data on the basis of information obtained invitro, it represents a powerful theoretical tool connecting in vitro and in vivo behavior.
