Some Fractal Aspects in Biopharmaceutics and Pharmacokinetics Review

The classical kinetic models dealt with homogeneous systems and homogeneous processes or what is called well-stirred systems. However, the thorough study of nature and the human body revealed the fractal nature of it, and the linearity between the input and output is no longer valid. System of fractal and disordered nature demanded satisfactory under dimensional constrains. In this review, some of those efforts are discussed. Fractal aspects in drug absorption from the gastrointestinal tract after oral dosage form was described by many models, here we emphasized only those which related to the derivation of time-dependent absorption rate coefficient. Also, for drug distribution, the description of heterogeneity of process related to blood vessel structure was proposed. For drug elimination, the emphasis was put on the derivation of a new form of Michaelis - Menten equation based on time dependency and fractal rules to describe drug metabolism as a key elimination process.