An introduction to key concepts in drug delivery

Drug delivery is a broad and active area of research involving a multidisciplinary approach whose integrative aim is to assist in reaching the optimization of drug efficacy by effective delivery of the active drug component to its target tissue while minimizing toxicity. The purpose of this chapter in particular and the book as a whole is to address clinical and engineering integration approaches for drug delivery systems. The clinical aspect involves understanding the unmet need and the clinical implications involved. It also requires understanding the individual clinical and biological differences of patients. Moreover, generating clinical and biological data is critical for drug delivery as this data can delineate the optimized pathway for a particular drug and its delivery system. In addition, pathophysiology of disease can affect drug delivery; for example, inflammation may greatly alter the disposition of a medication, thereby modifying its efficacy, such as drug penetration to a particular tissue [1-3]. The engineering aspect, on the other hand, involves either the manipulation of the physicochemical properties of the active ingredient or formulation (pharmaceutical engineering) or the fabrication of devices based on mechanical engineering principles in order to achieve a desired pharmacokinetic-pharmacodynamics profile of the active principle (drug delivery devices).