ABSTRACT
The attractive pharmaceutical concept of “magic bullet” introduced by Paul Ehrlich precisely one hundred years ago is nally getting a distinctive shape due to the recent developments in the area of drug delivery systems (DDS). This earlier idea was lately transformed into the concept of “magic pill” based on assisted targeted delivery and controlled release of therapeutic amounts of drugs in the site of disease. Administration of minute drug- lled containers instead of low-molecular-weight (MW) drugs has an obvious advantage in preventing nonspeci c drug distribution and toxicity in
healthy tissues. The two principal requirements are for them to be biodegradable and small to pass through microcapillaries without blocking ow and oxygen supply to the tissues. Enormous efforts were recently applied to the rational design and evaluation of various microsized (0.5-5 mm in diameter) and nanosized (<0.5 mm in diameter) drug carriers in vitro and in vivo.
