National Institute of General Medical Sciences
This booklet from the National Institutes of Health’s National Institute of General Medical Sciences discusses the many different ways medicines work in the body and how this information guides the hunt for drugs of the future. It is available in e-pub (http://publications.nigms.nih.gov/epubs/MedicinesByDesign.epub) and PDF (http://publications.nigms.nih.gov/medbydesign/medbydesign.pdf) formats.
Read this work at the World Public Library (library card needed).