Therapeutic uses of a variety of drug carrier systems have significant impact on the treatment and potential cure of many chronic diseases, including cancer, diabetes mellitus, rheumatoid arthritis, HIV infection, and drug addiction. Scientific efforts in the above are of a multidisciplinary nature involving the physical, biological, medical, pharmaceutical, and engineering fields, and biomedical materials. With the vast increase in the numbers of papers and the tendency to fragmentize science, it becomes increasingly difficult to keep abreast of the literature, and even more difficult to sort out and to evaluate the importance and sometimes the reliability of the data, especially in cases where proprietary considerations are involved. Abstracts and non-critical articles often do not provide a sufficiently reliable basis for the proper assessment of a given field without the additional perusal of the original literature. The aim of Critical Reviews in Therapeutic Drug Carrier Systems is to bridge this gap by publishing authoritative, objective, and comprehensive multidisciplinary critical review papers with emphasis on clinical applications. Both invited and contributed articles are considered for publication. The Journal will be of benefit to manufacturers, health-care providers, researchers, and patients, and will have wide appeal to clinicians, scientists, and engineers working in the field of drug carriers.