title: Application of mathematical modeling in sustained release delivery systems.
abstract: BACKGROUND
  This review, presenting as starting point the concept of the mathematical modeling, is aimed at the physical and mathematical description of the most important mechanisms regulating drug delivery from matrix systems. The precise knowledge of the delivery mechanisms allows us to set up powerful mathematical models which, in turn, are essential for the design and optimization of appropriate drug delivery systems.
  
  
  METHODS
  The fundamental mechanisms for drug delivery from matrices are represented by drug diffusion, matrix swelling, matrix erosion, drug dissolution with possible recrystallization (e.g., as in the case of amorphous and nanocrystalline drugs), initial drug distribution inside the matrix, matrix geometry, matrix size distribution (in the case of spherical matrices of different diameter) and osmotic pressure. Depending on matrix characteristics, the above-reported variables may play a different role in drug delivery; thus the mathematical model needs to be built solely on the most relevant mechanisms of the particular matrix considered.
  
  
  CONCLUSIONS
  Despite the somewhat diffident behavior of the industrial world, in the light of the most recent findings, we believe that mathematical modeling may have a tremendous potential impact in the pharmaceutical field. We do believe that mathematical modeling will be more and more important in the future especially in the light of the rapid advent of personalized medicine, a novel therapeutic approach intended to treat each single patient instead of the 'average' patient.
authors.affiliation: University of Trieste, Department of Engineering and Architecture , Via Valerio 6/A, I - 34127, Trieste , Italy +39 040 558 3435 ; +39 040 569823 ; mariog@dicamp.univ.trieste.it.
authors.forename: Mario
authors.initials: M
authors.lastname: Grassi
authors.forename: Gabriele
authors.initials: G
authors.lastname: Grassi
mesh_terms: D003692:Delayed-Action Preparations; D016503:Drug Delivery Systems; D006801:Humans; D008962:Models, Theoretical
chemical_list: D003692:Delayed-Action Preparations
keywords: delivery mechanisms; drug delivery; mathematical modeling; matrices