Historical perspective on advanced drug delivery: how engineering design and mathematical modeling helped the field mature.

We review the early developments in drug delivery from 1960 to 1990 with emphasis on the fundamental aspects of the field and how they shaped the collaboration of pharmaceutical scientists, chemists, biologists, engineers and medical scientists towards the development of advanced drug delivery systems. Emphasis is given on the advances of biomaterials as drug delivery agents and on the use of design equations and mathematical modeling to achieve a wide range of successful systems.