Some perspectives on targeted delivery with prodrugs.

Targeted delivery using prodrugs is becoming an important means for studying approaches to the efficient delivery for complex and often toxic molecules to specific sites within the body. Especially true for polymeric prodrugs containing targeting moieties, the future offers many possibilities for improvement of the therapeutic ratio by delivering drugs exclusively to diseased cellular and subcellular components within the organism. The fact that this type of research is highly interdisciplinary in nature requires the creative input of the biology disciplines as well as chemistry and pharmaceutical science. Our perspective on what constitutes the true delivery system, as it applies to targeted delivery, needs to be redefined. The use of the prodrug to target drug molecules to specific sites is merely the chemical delivery device that has been conceived and designed after considering the implications of those biochemical, physiological, and immunological processes that ultimately affect the transport and distribution of the prodrug within the host organism.