What is a drug delivery system and what are its characteristics?

Drug Delivery Systems (DDS) refers to different forms of administration of various therapeutic drugs used by people in the process of preventing and treating diseases, which was called dosage forms in pharmacy before 196s. Such as injection, tablet, capsule, patch, aerosol, etc. With the progress of science, the development of dosage forms has gone far beyond its original connotation, which needs to be expressed by terms such as drug delivery system or Device, that is, various dosage forms originally made of drugs and accessories can no longer meet the needs of clinical treatment. Some drugs are made into infusion systems for use, while others are made of titanium alloys for implantation in the body, which makes clinical medication more ideal. In order to overcome the defect that the effective blood concentration of common preparations is short, a series of new preparations have appeared, such as long-acting injection, oral long-acting drug delivery system or sustained/controlled release preparation, transdermal drug delivery system and so on. Due to the characteristics of sustained/controlled release preparation, its market prospect is promising. The slow-release preparations collected by Medical Education Network usually refer to preparations that can slowly release drugs in the body after oral administration to achieve effective blood concentration and can last for a long time. Controlled-release preparation means that the release rate is only controlled by the drug delivery system itself, and it is not affected by external conditions, such as pH, enzymes, ions, gastrointestinal peristalsis and other factors. It is a preparation that controls the release of drugs according to a designed program, such as osmotic pump with zero-order release, pellets with pulse release, tablets or capsules with colon-specific release, and insulin delivery device with automatic release. There are also some documents that do not strictly distinguish between sustained-release and controlled-release preparations, and they are collectively called sustained/controlled-release preparations.