ABSTRACT
Advances in drug development and site-specic delivery have evolved in several phases. It began with the botanical phase of human civilization, via the synthetic chemistry era, and is presently in the biotechnology era. Researchers are continuously developing new and more powerful drugs. Increasing attention is being given to the delivery methods of these active substances. Drug delivery systems transport drugs in the biological system. The delivery system not only carries a single or multiple therapeutic agents, but also performs certain functions to increase the effectiveness of drug therapy.
